System for providing surgical access

ABSTRACT

One embodiment is directed to a system for advancing a needle into a tissue structure, comprising: an elongate needle member having a tapered distal tip; an insertion member having proximal and distal ends, the distal end being coupled to the elongate needle member, and the proximal end being configured to be manipulated by an operator; and a tissue interface indentor member coupled to the insertion member and operatively coupled to the elongate needle member, the tissue interface indentor member comprising a distally protruding shape feature configured to contact one or more portions of the tissue structure adjacent to the distal tip of the elongate needle member and change an available angle of penetration between such portions and the distal tip of the elongate needle member as the distal tip is inserted into tissue structure.

RELATED APPLICATION DATA

The present application claims the benefit under 35 U.S.C. §119 to U.S.provisional patent application Ser. Nos. 61/384,659, filed Sep. 20,2010, and 61/484,175, filed May 9, 2011. The foregoing applications arehereby incorporated by reference into the present application in theirentirety.

FIELD OF THE INVENTION

This invention is related generally to tissue structure access and woundclosure systems, and more particularly to configurations for accessingand closing walls of tissue structures, such as the walls of thecavities of the heart during a trans-apical procedure.

BACKGROUND

Minimally invasive diagnostic and interventional procedure prevalence inUS and foreign hospitals continues to increase, as does the demand forcertain procedures which involve placement of relatively large devicesinto targeted locations within tissue structures of criticality.Procedures such as aortic valve replacement conventionally have beenaddressed with open surgical procedures which are highly invasive. Morerecently, such procedures have been attempted using natural lumen (i.e.,through large blood vessels after an initial surgical transcutaneous orpercutaneous access to such vessels) access and delivery systems.Referring to FIG. 1, such systems typically are configured, for example,to reach the aortic valve (12) location inside of the heart (2) from anantegrade approach, which generally requires navigating instrumentationthrough three of the four chambers of the beating heart (the rightatrium 22, left atrium 8, and left ventricle 20, by way of the mitralvalve 10 and atrial septum), or from a retrograde approach, whichgenerally requires navigating instrumentation along the aortic arch,from the descending aorta (4) to the ascending aorta (6) and adjacentthe aortic valve (12). Each of these approaches presents certainclinical challenges to the surgical team, some of which may be avoidedby using what is referred to as a transapical approach, whereby thesurgeon creates transcutaneous access to the region around the apex ofthe heart (26) with a surgical thoracotomy, followed by direct access tothe left ventricle (20) using a needle or other device aimed to accessthe left ventricle (20) around the left ventricular apex (24), which maybe followed by one or more dilating instruments to create a temporaryaccess port to the left ventricle. Aspects of a conventional accessprocedure are illustrated in FIG. 2, wherein a needle device (34) ispuncturing the muscular heart wall (30) to gain access to the leftventricle (20) around the location of the left ventricular apex (24).Also shown is a guidewire (36) which may be advanced (38) toward andthrough the aortic valve (12) to assist with diagnostic andinterventional aspects of the procedure. Using these and otherinstruments such as dilators, this left ventricular access port may beutilized, for example, to replace an aortic valve if bleeding and tissuedamage around the access port can be successfully mitigated during suchprocedure. Subsequent to such a procedure, the instrumentation needs tobe removed and the access port closed, usually leaving a prothetic valveor portion thereof behind. The successful closure of a transapical woundon a beating heart of a patient is obviously of high criticality to sucha procedure, as is the minimization of loss of blood. Conventionaltransapical closure techniques typically involve the placement of smallsutures to create a purse-string type effect to close the wound as theinstrumentation is withdrawn, and it may be very difficult to repeatablycreate acceptable closures using these techniques without a largerthoracotomy or improved instrumentation. In other words, one of the keychallenges to transapical intervention remains transapical woundclosure. Indeed, it is believed that transapical access may provideenhanced stability and control during procedures such as aortic valvereplacement, due to the fact that the operator may have a relativelydirect mechanical connection with the pertinent instrumentation,relative to the connection that he may have using, for example, anantegrade or retrograde vascular approach with more compliant cathetertype tools. For this reason, it is even more desirable to successfullyaddress the challenges of transapical access and closure. Further, itwould be desirable to have a wound or access closure technology that wasapplicable not only to transapical access port closure, but also otherclosure demands pertinent to other surgical interventions of the humanbody wherein wounds or ports are created, such as in gastrointestinal orgynecological surgery.

SUMMARY OF THE INVENTION

One embodiment is directed to a system for advancing a needle into atissue structure, comprising: an elongate needle member having a tapereddistal tip; an insertion member having proximal and distal ends, thedistal end being coupled to the elongate needle member, and the proximalend being configured to be manipulated by an operator; and a tissueinterface indentor member coupled to the insertion member andoperatively coupled to the elongate needle member, the tissue interfaceindentor member comprising a distally protruding shape featureconfigured to contact one or more portions of the tissue structureadjacent to the distal tip of the elongate needle member and change anavailable angle of penetration between such portions and the distal tipof the elongate needle member as the distal tip is inserted into tissuestructure. The elongate needle member may comprise a shape selected fromthe group consisting of: a substantially straight shape, an arcuateshape, and a helical shape. The elongate needle member may comprise afirst helical member that defines an inner helix diameter that issubstantially constant across the length of the helical member. Theelongate needle member may comprise a first helical member that definesan inner helix diameter that varies across the length of the helicalmember. The inner helix diameter may be between about 5 mm and about 60mm. The inner helix diameter may be between about 10 mm and about 20 mm.The elongate needle member may comprise a first helical member that iscomprised of an elongate member formed into the helical shape, theelongate member having an outer diameter. The elongate member may have across sectional shape selected from the group consisting of: a circularcross section, an elliptical cross section, a square cross section, anda rectangular cross section. The outer diameter may be between about 0.5mm and about 3 mm. The helical shape may comprise a number of helicalturns advanceable into tissue relative to the insertion member that isbetween about 1 and about 3. The helical shape may have a substantiallyconstant helix pitch along the length of the helical shape. The helicalshape may have a substantially variable helix pitch along the length ofthe helical shape. The helical shape may have a substantially constanthelix pitch along the length of the helical shape. The helical shape mayhave a substantially variable helix pitch along the length of thehelical shape. The helix pitch may be between about 5 mm and about 20mm. The helix pitch may be between about 7 mm and about 13 mm. Thedistal end of the first helical member may comprise a sharpened tipconfigured to easily dive into and cross portions of the tissuestructure. The elongate member may comprise a solid cross-sectionalconstruct. The elongate member may comprise a tubular construct havingan inner diameter and as well as the outer diameter. The elongate membermay comprise a material selected from the group consisting of: stainlesssteel, nitinol alloy, titanium, cobalt chrome, and polymer composite.The elongate member may comprise a material selected from the groupconsisting of: stainless steel, nitinol alloy, titanium, cobalt chrome,and polymer composite. The insertion member may comprise a substantiallyrigid construct. The insertion member may comprise a flexible construct.The distally protruding shape feature may be configured to concentrateinterfacial stresses upon the tissue structure such that the portions ofthe tissue structure adjacent the distal tip of the elongate needlemember become locally strained about the distally protruding shapefeature as the distally protruding shape feature is advanced intocontact with the adjacent tissue structure portions; and wherein thecontact between the adjacent tissue structure portions and the distallyprotruding shape feature locally increases the available angle ofpenetration defined between the needle and a surface of the adjacenttissue structure portions. At least one surface of the distallyprotruding shape feature may comprise a surface configuration selectedfrom the group consisting of: a portion of a spherical surface, a linearramp surface, an arcuate ramp surface, a multi-stepped ramp surface, anda single-stepped ramp surface. The surface configuration may behelically wrapped about a longitudinal axis of the helical member. Atleast one surface of the distally protruding shape feature may comprisea substantially perpendicular leading surface. The distally protrudingshape feature may have a cross sectional profile comprising a crosssectional shape selected from the list consisting of: a rectangle, asquare, a half circle, a triangle, a polygon, a rounded rectangularshape, a rounded square shape, and a multi-arcuate shape. The distallyprotruding shape feature and distal tip of the elongate needle membermay be operatively coupled such that the distal tip is movably coupledthrough a portion of the distally protruding shape feature. The distaltip substantially may bisect the portion of the distally protrudingshape feature. The distally protruding shape feature and distal tip ofthe elongate needle member may be operatively coupled such that thedistal tip is movably coupled adjacent a portion of the distallyprotruding shape feature. The distal tip of the elongate needle membermay be configured to follow a path substantially parallel to the surfaceconfiguration of the distally protruding shape feature. The distallyprotruding shape feature may comprise one or more tissue tractionfeatures configured to prevent relative motion between the distallyprotruding shape feature and portions of the tissue structure with whichit may be directly interfaced. At least one of the one of the one ormore tissue traction features may comprise a barb.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates aspects of the human heart anatomy.

FIG. 2 illustrates a conventional transapical access procedure.

FIGS. 3A to 3K illustrate various aspects of an experimentalconfiguration.

FIGS. 4A to 4P illustrate various aspects of a compound helical closureconfiguration featuring a single helical member.

FIGS. 5A to 5I illustrate various aspects of a compound helical closureconfiguration featuring two helical members configured to simultaneouslydeploy two sutures and two anchor elements.

FIG. 6 illustrates an embodiment wherein one or more tools may beinstalled and utilized before installation of a helical closureassembly.

FIGS. 7A to 7B illustrate a two-suture helical closure with anchoringelements deployed partially across the subject tissue wall.

FIGS. 8A to 8B illustrate a two-suture helical closure with anchoringelements across the subject tissue wall.

FIG. 9A illustrates a suture embodiment having barbs along a significantportion of its length; FIG. 9B illustrates a suture embodiment havingbarbs only on its distal portion.

FIGS. 10A to 10F illustrate aspects of an experiment utilizingembodiments such as those shown in FIGS. 3A to 3H.

FIGS. 11A to 11J illustrate aspects of an experiment utilizingembodiments such as those shown in FIGS. 4A to 4N.

FIGS. 12A to 12C depict techniques for implementing various embodimentsof the subject helical closure configurations.

FIG. 13 illustrates one needle structure embodiment having a channelformed therein for localized suture storage.

FIG. 14 illustrates one needle and suture arrangement wherein a sawtoothpattern is utilized for localized length storage functionality.

FIGS. 15A-15J illustrate various aspects of a compound helical closureconfiguration featuring a single helical member and a one-way tensionretainer.

FIG. 16 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIGS. 17A-17F illustrate various aspects of a compound helical closureconfiguration featuring a pair of helical members and acontrollably-locking tension retainer.

FIG. 18 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIGS. 19A-19Z-8 illustrate various aspects of a compound helical closureconfiguration featuring a pair of helical members and a two-way/one-waycontrollably-advanceable tension retainer.

FIG. 20 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIG. 21 illustrates various aspects of one embodiment of a helicalclosure configuration having a relatively shallow angle of approach.

FIG. 22 illustrates various aspects of one embodiment of a helicalclosure configuration having a relatively large effective angle ofapproach.

FIGS. 23A and 23B illustrate aspects of one embodiment of a helicalclosure configuration having a relatively large effective angle ofapproach and features to decrease slipping of nearby tissue structures.

FIG. 24 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIG. 25 illustrates a configuration wherein slack is utilized bothproximally and distally to a deployed helical suture pattern.

FIG. 26 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIG. 27 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIGS. 28A-28D illustrate configurations wherein temporary suture memberfixation may be employed.

FIG. 29 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIG. 30 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIG. 31 illustrates a technique for implementing various embodiments ofthe subject helical closure configurations.

FIG. 32 illustrates an embodiment of an anchor member featuring a flextail configuration.

DETAILED DESCRIPTION

Referring to FIGS. 3A through 3H, various aspects of embodimentsassociated with a transapical access and closure system are depicted,including certain experimental and illustrative configurations. As shownin FIG. 3A, a transapical access assembly is depicted comprising aneedle (34) placed through an elongate dilator member (42), which isslidably positioned through a working lumen of an introducer sheath (44)which may be manipulated using a proximal handle or hub (46). Theassembly has been placed through a thoracotomy created in the chest wall(40) of a patient, and directed toward a location on the heart (2) thatis determined to be close to the apex (24) of the left ventricle (20)using information derived from sources such as anatomic markers,preoperative diagnostic imaging information, such as radiography and/orfluoroscopy, and intraoperative imaging information derived, forexample, from radiography, endoscopy, and/or fluoroscopic imaging ofportions of the access assembly which may be radioopaque (or radioopaquemarkers which may be fastened to portions of the assembly in oneembodiment). Referring to FIG. 3B, a close-up view of certain structuresdepicted in FIG. 3A is shown. FIG. 3C illustrates that with atransventrical, or more specifically, transapical, approach, theelongate guiding member (34), such as a needle (which may besubsequently utilized to advance a guidewire), may be the firststructure advanced (50) into or across the heart wall (48). FIG. 3Dillustrates a close up detail view of one embodiment wherein an elongateguiding member comprises a straight needle (32) that has been advanced(50) across the heart wall (48) with a suture (52) helically wrappedaround it and terminating near the distal end of the straight needle(32) with an anchor element (54). In experiments, we have found thatcertain variations of such a configuration may be utilized to advance asuture (52) into a position partially or entirely across a tissue wall(48) with the spiral configuration retained on the way in (indeed,tension, friction, and pressure applied to the helically wound suture 52tends to keep it in its helical configuration during entry; additionalproximal tension on the suture 52 may also be utilized to assist inretention of the spiral configuration). Further, we have demonstratedthat by withdrawing the needle (32), the anchor element (54) retains thedistal suture (52) position and the suture (52) is unfurled and leftbehind in a substantially helical or “coiled” configuration. FIGS. 3Eand 3F, for example, illustrate that upon withdrawal (56) of thestraight needle (32) and release of suture tension which may be keepingthe suture helically in place relative to the guiding member (34), theanchor element (54) configured to prevent withdrawal of the distal endof the suture (52) and the unfurling action of the suture leave a coiledor helical suture (52) configuration in place. We have also found thatthe retained helical suture (52) pattern accommodates significantlongitudinal expansion (i.e., in the range of 200% to 300% strain)without applying significant slicing type loads to nearby tissuestructures, as demonstrated in FIGS. 3G and 3H, wherein the helicalsuture (52) pattern is substantially retained as the tissue wall (48) orpertinent portion thereof is strained from an initial length of “L” to alength of “L+deltaL”. Referring to FIG. 3G, with the suture in itsdeployed coiled configuration with adjacent tissues substantiallyunloaded, the coil diameter of the helical suture configuration is maybe represented by “CD1” (61). Referring to FIG. 3H, with elongation (64,62) of the nearby tissue structure (48), the localized length storageprovided by the coiled configuration provides extra length fairlyuniformly across the suture, which prevents cutting loads against thenearby tissue, and which results in a smaller coil diameter (63) asfurther length is extracted out of the coiled configuration, ultimatelyleading to a substantially uncoiled, or completely uncoiled, linearsuture configuration without additional localized suture length storage.This notion of localized length storage may be utilized quiteeffectively in surgical procedures wherein it may be desirable toincrementally and efficiently close ports, wounds, and the like withoutlaceration of nearby tissue, which may be associated with moreconventional suture-tightening configurations. In other words, manyconventional “purse-string” type suture configurations lead tosimultaneous motion and loading at the interface between suture materialand tissue, which can lead to undesirable cutting of the tissue. Withadequate localized length storage, incremental tightening may beconducted with significantly reduced risk of tissue cutting due to thefact that the coiling facilitates tightening with reduced interfacialloading until the very end of the tightening range, at which point verylittle motion is required to complete the requisite tightening paradigm(depending upon the pertinent tissue structures, desired loading, etc).Referring to FIGS. 3I-3K, this helical configuration for localizedlength storage may be utilized not only with straight needle members(32), as in FIG. 3I, but also with curved needle members (28), as inFIG. 3J, and helical needle members (66), as in FIG. 3K.

FIGS. 4A-4P depict aspects of one embodiment of a compound helicalclosure configuration utilizing a suture (52) helically wound (“first”or “suture helix”) around a helical needle member (66—“second” or“needle helix”), as previously shown in FIG. 3K. Further embodiments aredisclosed in FIGS. 5A-9B, while FIGS. 10A-11J depict images of some ofour confirming experiments, and FIGS. 12A-12C depict aspects of methodsfor utilizing related configurations in surgical procedure embodiments.

Referring to FIG. 4A, a deployment, or delivery, member (14) is shownwith a compound helical configuration at its distal end, comprising asuture, or suture member, (52) helically wound around a helical member(66). A tensioning element, such as an elongate tubular member defininga lumen therethrough, (16) is proximally coupled to the suture (52), anda manual tensioning interface (18) is coupled to the proximal aspect ofthe tensioning element (16) to allow an operator to apply tension to thesuture (52) from a proximal location. FIG. 4B shows a close-up view ofthe distal portion of the deployment configuration of FIG. 4A, with thecompound helical suture (52) configuration, distal anchoring element(54), and elongate tracking member, or “helical member guiding member”,(68) more visible. The elongate tracking member (68) may be utilized inan “over the wire” or “over the needle” configuration relative to anassociated needle or guidewire, and particularly in the scenario of aguidewire (which is generally substantially more flexible than aneedle), is configured to maintain the tracking of the helical needlemember (66) during advancement (i.e., to prevent “walking around” of thehelical needle, as may be possible with only a flexible guidewire fortracking). The distal end of the helical member guiding member (68) maybe substantially straight, as depicted, and define a longitudinal axisthat is substantially coincident with that of the helical member. Thehelical member guiding member may be coupled to the delivery member,which is coupled the helical member, as shown; the helical memberguiding member may also be immediately coupled to the helical member.

Referring to FIG. 4C, a configuration such as that depicted in FIGS. 4Aand 4B may be utilized to deploy a compound helical suture across atissue structure wall (48) or portion thereof. In the depictedembodiment, an elongate guiding member (34) such as a needle orguidewire has already been advanced across the wall (48), but in otherembodiments, this need not be the case (i.e., the tracking member 68itself may serve as a guiding member to keep the assembly on track).Indeed, one of the key advantages of the depicted configuration is thatit may be deployed to pre-install a helical closure suture configurationthat may be generally inspected and examined before the installation orinsertion of other diagnostic and/or interventional tools. In otherwords, before taking the risk of installing and utilizing generallylarger tools, which require a larger wound, a closure paradigm may bepre-installed and inspected beforehand, thus taking some of the risk outof the procedure.

Referring again to FIG. 4C, in the depicted embodiment, an elongateguiding member (34) has been installed, and the elongate tracking member(68) is being guided in an “over the wire” form as the deployment member(14) is advanced (70) and rotated (72). Referring to FIG. 4D, withfurther advancement (70) and rotation (72) to rotationally advance thehelical member (66), the suture (52) compound helical portion isadvanced across a portion of the tissue wall (48) and the anchoringelement (54) is positioned within the tissue wall (54). In oneembodiment, the assembly may be loaded in both compression and rotation(i.e., both pushed and torque simultaneously); in another embodiment,only a rotational load is used to advance the assembly. Preferably thedistal ends of the needle members are sharpened to easily dive into across portions of the subject tissue structure, and the anchor membersare configured to have at least one shape feature that is configured toslide in easier than it is to slide out (i.e., it preferably will resistretraction, either through a barbed type of feature, or by changingposition and/or orientation relative to the surrounding tissue, as witha toggle bolt type of configuration, as described in further detailbelow). Preferably a reversal in needle member direction relative to thesurrounding tissue applies a reverse load on the anchor members whichcauses them to decouple from their insertion positions upon the helicalneedle members. In one embodiment, the needle member comprises an anchorcoupling portion that is locally decreased in outer diameter toaccommodate slidable coupling through a lumen defined through an anchor,such that the outer diameter of the anchor during advancement/deliverymay be sized substantially similar to the outer diameter of the helicalneedle.

In another embodiment, the anchoring element may be advanced completelyacross the tissue wall (48), as illustrated, for example, in FIGS. 8Aand 8B. The embodiment of FIG. 4D also features several sensorsconfigured to facilitate an operator's awareness of the positioning ofthe helical member (66) relative to the subject tissue. In the depictedembodiment, a first RF sensor (85) is coupled to the distal aspect ofthe helical needle member (66) to capture electrocardiogram (“EKG”)related signals which are detectable at the outer surface of the heart(the first RF sensor 85 may be operatively coupled via a lead 87disposed through the needle 66 and through the proximal deploymentmember 14 to an EKG-related signal processing system 92, such as thoseavailable from the Prucka division of General Electric, Co.). With sucha configuration, as the helical needle (66) first comes into contactwith the outside of the heart, such contact may be detected. Theconfiguration in FIG. 4D also features a similar second RF sensor (86)similarly coupled to the EKG system (92) via a lead (90) and positionedat the distal aspect of the deployment member (14) such that it willcontact the outside of the heart or other tissue structure (48) when thehelical member (66) is fully advanced (70, 72). The depicted embodimentalso features an optical coherence tomography (“OCT”) system (94)configured to use interferometry computation and an optical fiber (88)terminated at a lens (86) to compute proximity to the nearby tissue wall(48) and other structural thresholds, such as the opposite wall of thetissue structure. As described above, the suture (52) may be tensioned(80) during deployment to retain the helical interfacing of the suture(52) with the helical member (66).

Referring to FIG. 4E, with the compound helical aspect of the suture(52) in a desired location across the tissue wall (48), the deploymentmember (14) may be retracted by withdrawing (76) and counterrotating(74) it (or, as discussed above, simply counterrotating) while anyproximally applied tension on the suture (52) is released, thus applyinga reverse load to the anchor member which causes it to become decoupledfrom the helical needle member (66) and assume a load resistingconfiguration (by rotating, expanding, loading a barb or otherprojecting member, etc, as described below), causing the suture (52) toseparate from the needle member (66) and remain coiled in place, stillcoupled to the anchor member, as shown in FIG. 4F. As noted above inreference to the advancement of the helical needle assembly, theassembly may be advanced or retracted using either a combination ofcompressive or tensile loading (i.e., slight pulling for retraction orpushing for advancement—on a proximal manual interface) added torotational loading (i.e., torque to a proximal manual interface eitherclockwise or counterclockwise)—or with only rotational loading (i.e.,simply screwing the assembly in and out without concomitant tensile orcompressive loading). FIG. 4F shows the deployment member (14) andhelical member (66) completely withdrawn from the tissue wall (48),leaving behind the anchor element (54) and the suture (52) in a compoundhelical pattern (“compound” in that the suture remains helically coiled,and the coil remains in a helical configuration). FIG. 4G shows thedeployment member (14) and helical member (66) completely removed, withthe elongate guiding member (34) remaining in place, along with thedeployed compound helical suture (52) and suture anchor element (54).

FIG. 4H depicts an orthogonal view of the deployed compound helicalsuture (52) and suture anchor element (54), which are configured atdeployment, by virtue of the geometry of the helical member (66), tohave an outer shape width that may be represented as “W” (96). Theun-tensioned compound helical suture (52) configuration has an unloadedcoil diameter of “CD1” (61). As described above in reference to ourexperimental findings, this deployment paradigm provides significantflexibility for diagnostic and interventional paradigms that follow, asthe tissue/suture/anchor assembly may be strained in many directionsquite significantly without disturbing the generally compound helicaldeployment of the suture, and with significantly less risk of laceratingtissue during expansion or tightening due to the localized lengthstorage provided by the coil configuration. For example, as shown inFIG. 4I, a dilator (42) is advanced (100) over the elongate guidingmember (34). The relatively large outer shape of the dilator urges (98)the surrounding tissue outward, and generally causes the orthogonaldimension of the larger suture helix to become greater than “W”, butgenerally does not take the suture (52) out of the compound helicalconfiguration. With the localized length storage being utilized toprovide the extra length needed to increase to a larger included tooldiameter, the suture (52) coil diameter decreases. Referring to FIG. 4J,an even larger tool (102), say having outer diameter of “W+deltaW” (104)may follow after the dilator (element 42 of FIG. 4H) has been proximallyremoved (i.e., through a sheath with hemostatic valve). This larger toolshape further locally urges (106) the tissue outward (the largerdiameter causing further decrease of the coil diameter due to furthertake up of the localized length storage; perhaps to a new, smaller coildiameter of “CD2”), but the compound helical patterning of the suture(52) is retained while the tool (102) is in place to, for example,deploy a prosthetic heart valve, etc. Referring to FIG. 4K, when atightening and/or closure of the wound is desired (for example, it maybe desirable to tighten the wound to prevent leaks during the diagnosticand/or interventional steps using the aforementioned tool 102), theproximal aspect of the suture (52) may be tensioned (108), causing bothof the involved helical shapes to shrink: the larger helical shape ofthe coils shrinks around the engaged tool, and the coiling helix itselfshrinks away with tensioning as the localized length storage is used up.This combined helical shrinking action causes the captured wound ordefect to close, as shown in FIGS. 4L and 4M, wherein the tapered shapeof a dilator inserted (i.e., through a hemostatically valved sheath)after withdrawal of the tool (element 102 in FIG. 4I) may be utilizedalong with a successive tightening (108) interplay with the suture (52)to close the wound or defect behind the withdrawing (110) dilator (42).In other words, successive rounds of dilator withdrawal (110), thensuture tightening (108) may be utilized to incrementally close the woundor defect. The suture (52) in FIGS. 4L-4P is shown with the localizedlength storage effected used up, and the suture forming a generallyuncoiled configuration as it continues to hold the larger helicalpattern around the captured wound and tools. Referring to FIG. 4M, withthe needle (34) and dilator (42) retracted, a guidewire (36) may be leftin place and the wound substantially closed around the guidewire (36),as shown in FIGS. 4M-4O, to provide an easy return access subsequent toa period of observation. For example, in an embodiment wherein aprosthetic valve has been placed with the aforementioned tools (102), itmay be desirable to close the wound and leave a guidewire (36) in placeduring a few minutes of observation of the valve prosthesis in situ, toconfirm adequate function while also having a fast and efficient returnmeans (the guidewire 36) should this be required.

Referring to FIG. 4N, with only the anchor element (54), guidewire (36),and suture (52) left behind, the suture (52) may be tied into a knot andterminated at the proximal wall of the tissue structure (48), or aterminating device (114) may be advanced (116) along the suture andsnugged into place against the wall (i.e., to retain a desired level oftension in the deployed suture 52), followed by cutting of the proximalun-needed portion of the suture, as shown in FIG. 4O. In anotherembodiment, two or more compound helical sutures may be similarlydeployed in sequence before advancement of the dilator (42) and/or tool(102); for example, in one embodiment, two compound helical sutures maybe sequentially deployed in different helical directions; in anotherembodiment, the two may be in the same helical direction but at slightlydifferent winding offsets; many embodiments are within the scope of theinvention. Referring to FIG. 4P, subsequent to confirmation that noadditional intervention is necessary, the guidewire (36) may be removed(37).

Referring to FIGS. 5A and 5B, an embodiment is depicted wherein twohelical members (66, 67) coupled to the same deployment member (15) buthaving different helical radii (see, for example, the top orthogonalview of FIG. 5C) may be utilized to simultaneously install, via rotation(180) and insertion (182), two compound helical sutures (52, 53), eachhaving its own anchoring element (118, 120). The distal portion of suchconstruct showing the helical members (66, 67) and anchors (118, 120),but not the compound helically wound sutures (elements 52 and 53 of FIG.5A) is shown in orthogonal close-up view. Referring to FIGS. 5E-5I,various anchoring element configurations (118, 122, 126, 122, 130) maybe utilized to retain a distal suture end within or across a tissuestructure wall. Each of the configurations of FIGS. 5E through 5H has ageometry that prefers to be advanced in one direction, but resistsretraction in the opposite direction when placed against viscoelastictissue, such as that of the heart or other human tissues. Element 122represents one or more coupling holes to facilitate coupling with thepertinent suture (52, 53). The configuration of FIG. 5I is a simple knot(130) tied in the end of the suture (52) with enough geometric bulk toprevent pullback through the subject tissue. Referring to FIG. 32,another anchor member embodiment is depicted, this one (406) comprisinga tubular body comprising Nitinol superalloy heat formed in anarcuate/helical shape to match the helical needle member to which it isto be paired, with a Nitinol flex tail (404) configured to resistretraction, and a tapered leading geometry (402) configured to assistwith easy insertion/advancement. A titanium suture coupling ring, orring member, (398) defining a suture-coupling aperture (408) is coupledto the body using a press fit, welded (such as tack welded), or adhesivejunction. The flex tail (404) is configured to flex inward toward thehelical needle member during insertion, and to flex outward to resistretraction and assist the anchor member body (400) in rotating to anorientation approximately perpendicular to that assumed by the anchormember body (400) during insertion (i.e., toggling to a reorientationthat resists retraction). Preferably the eyelet (408) is optimallypositioned to urge the anchor member body into rotational movementrelative to the surrounding tissue upon tensile loading of theintercoupled suture member. In the depicted embodiment, the eyelet (408)is displaced apart from a longitudinal axis of the body andapproximately in the middle of the body longitudinally. Anotherembodiment may comprise two or more flex tails. The superalloy (such asNitinol) flex tail, or tails, may be shape set to a projecting position(i.e., projecting out and away from the body), but configured to bedelivered in an elastically compressed form (i.e., with the taildeflected toward the body of the anchor member) within the superelasticthermal range for the alloy.

The anchor may comprise a metal selected from the group consisting of:titanium, stainless steel, cobalt chrome, and alloys thereof. The anchormay comprise a durable polymer selected from the group consisting of:polyethylene terepthalate, polyethylene, high density polyethylene,polypropylene, polytetrafluoroethylene, expandedpolytetrafluoroethylene, poly(ethylene-co-vinyl acetate), poly(butylmethacrylate), and co-polymers thereof. The anchor member may comprise abioresorbable polymer selected from the group consisting of: polylacticacid, polyglycolic acid, polylactic-co-glycolic acid, polylacticacid-co-caprolactone, poly(block-ethyleneoxide-block-lactide-co-glycolide), polyethylene glycol, polyethyleneoxide, poly(block-ethylene oxide-block-propylene oxide-block-ethyleneoxide), polyvinyl pyrrolidone, polyorthoester, polyanhydride,polyhydroxy valerate, polyhydroxy butyrate, and co-polymers thereof. Theanchor member may comprise a biological graft material, such as one thathas an origin selected from the group consisting of: another human, theparticular human, a non-human animal. The anchor member may comprise abioresorbable material selected from the group consisting of: porcinecollagen matrix, human collagen matrix, equine collagen fleece, gelatin,polyhyaluronic acid, heparin, poly(glucose), poly(alginic acid), chitin,chitosan, cellulose, methyl cellulose, hydroxyethylcellulose,hydroxypropylcellulose, carboxymethylcellulose; polylysine, polyglutamicacid, albumin, hydroxy apatite, cortical bone, cancellous bone,trabecular bone, bioceramic, ligament tissue, tendon tissue, duratissue, fascia tissue, pericardium tissue, thrombin, and fibrin.

Referring to FIG. 6, an another embodiment, a configuration such asthose described in relation to FIG. 4A-4N or 5A-5I may be advanced intoposition relative to a tissue wall after a tool (102) or other structurehas been deployed across the wall (48). Referring to FIGS. 7A-7B, aconfiguration such as those described in reference to FIG. 5A-5I or 6may be utilized to close a wound or defect after withdrawal of a tool(102), leaving behind only sutures (52, 53) and anchoring elements (118,120). Referring to FIGS. 8A-8B, it is important to note that the anchorsneed not be deployed within the midsubstance of the tissue structure tofacilitate a successful closure, but may be deployed across suchstructure, to reside at the opposite side of the subject wall (48).Referring to FIG. 9A, in one embodiment, the suture (52) may featurebarbs (132) to prevent slipping relative to the tissue structure (48)after deployment. Referring to FIG. 9B, a suture (52) embodiment isdepicted wherein only distal barbs (132) are utilized, and wherein theslip prevention provided by such barbs (132) obviates the need for ananchoring element (in other words, the embodiment shown in FIG. 9B is a“suture only” embodiment).

Referring to FIGS. 10A-10F, several images are depicted to illustratethe experiments we have completed to establish the flexibility andfunctionality of configurations such as those described in reference toFIGS. 3A-3H and 4A-4N. Referring to FIG. 10A, an elongate guiding member(34) is depicted with a suture (52) helically coupled thereto andterminated with a knot type anchoring element (130). Referring to FIG.10B, with proximal tensioning of the suture (52) and advancement of theconstruct through a simulated tissue structure (48) (which happens to beconveniently translucent for experimental purposes), the helicalpatterning of the suture (52) relative to the elongate member (34) isretained along substantially the entire length of the elongate member(34) during insertion (i.e., there is no “bunching”). Referring to FIGS.10C and 10D, with a release of the tensioning on the suture (52) andproximal withdrawal (134) of the elongate member (34), the suture (52)stays in place in its helical configuration. Referring to FIGS. 10E and10F, with relatively significant strain (exemplified here by a strainfrom length L 60 to length L+deltaL 62; recall that strains as high as200% to 300% or more may be accomodated), the helical patterning of thesuture (52) is generally retained. With the strain applied (from FIG.10E to FIG. 10F), the coil diameter (61) shrinks from CD1 to CD1 (63) asthe localized length storage is used up.

Referring to FIGS. 11A-11F, several images are depicted to illustratethe experiments we have completed to establish the flexibility andfunctionality of configurations such as those described in reference toFIGS. 4A-4P. Referring to FIG. 11A, a deployment member (14) coupled toa single helical member (66) and tracking member (68) is depicted, withthe tracking member (68) being advanced over an elongate guiding member(34) that has been deployed across a muscle tissue wall (48). A singlesuture (52) is helically wound around the helical member (66) andterminated with a knot anchoring element (130). FIG. 11B shows theconstruct being advanced and helically rotated into the tissue wall (48)with a tension being retained on the suture (52) from a proximallocation. Referring to FIG. 11C, on the opposite side of the tissue wall(48), the anchoring knot element (130) has reached the other sideadjacent to the location wherein the elongate guiding member (34) passesout of the tissue wall (48). Importantly, a uniform radial margin oftissue is retained between the helical needle (66) and the center of thewound adjacent the elongate guiding member (34) (i.e., the suture is notlacerating through the tissue). Referring to FIG. 11D, with release ofthe tension on the suture (52) and withdrawal/counterrotation of thedeployment assembly (66, 68, 14), the deployed suture (52) retains itscompound helical configuration within the muscle tissue. FIG. 11Edepicts a dilator (42) being advanced through the deployed suturecompound helix, and FIG. 11F depicts further advancement to illustratethat relatively significant dilation may be required to accommodatevarious diagnostic and/or interventional tools for variousprocedures—and that the compound helical suture configuration is quiteflexible in accommodating such large dilations, while retaining theability to be controllably tightened from a proximal location at anytime. It is worth noting that in our experiments, proximal tightening ofa single helical suture configuration (i.e., deployed with a helicalneedle but not with helical coiling in a helical pattern) resulted insignificant undesirable laceration of the tissue (particularly thetissue captured between the helical needle/suture and the woundcenterpoint), something that we have not found with the compound helicaldeployment, due to the localized length storage provided with thecoiling. FIG. 11G shows that a relatively large wound or port has beencreated following removal of the dilator (42). Referring to FIG. 11H,with a simple sheath (136) to isolate the free proximal portion of thesuture (52), tensioning of the suture (52) to execute a closure orpartial closure may be initiated. Referring to FIG. 11 i, with furthertensioning of the suture (52), the wound or port is closed around theelongate guiding member (34). Referring to FIG. 11J, on the oppositeside of the wall, the suture (52) and anchor element (130) based closureexecution is evident.

Referring to FIGS. 12A-12C, techniques for utilizing the subjectconfigurations are illustrated. Referring to FIG. 12A, afterpreoperative diagnostics and patient preparation (138), access may becreated (140) to the subject tissue structure (for example, athoracotomy may be created to access the wall of the heart, the heartwall being the subject of the subsequent wall crossing and closure). Thesubject tissue structure may be at least partially crossed (142) usingan elongate guiding member such as a needle, which may be navigatedutilizing various imaging, sensing, and/or navigation modalities. Theneedle may be followed by a guidewire (i.e., a guidewire advancedthrough the needle). One or more helical needle/suture assemblies may beadvanced (144) across a portion of the tissue wall following theelongate guiding member (or in another embodiment, without the assistantof a guiding member); then the helical member may be axially androtationally withdrawn to place an anchoring element and compoundhelical suture into a configuration wherein they may be subsequentlyutilized to effect a closure (146), and such configuration may beconfirmed (148) before further interventional steps. Subsequent toconfirmation that a closure configuration appears to be ready, a dilator(150) and/or other tools (152) may be advanced through the suture helix,thereby expanding the suture helix so that pertinent diagnostic and/orinterventional steps may be accomplished, such as the installation of aheart valve. Subsequently, the dilator may be re-inserted (i.e., using ahemostatically-valved sheath) in place of the diagnostic and/orinterventional tools (154), and the tapered outer shape of the dilatormay be utilized to effect an incremental tightening of the wound orport. A guidewire may be left in place as a “test closure” isaccomplished around the guidewire to permit observation of theintervention while also permitting easy re-access. The closure may becompleted with full withdrawal of the dilator, needle, and guidewire,and proximal fixation of the suture end or ends to retain tension (156).

Referring to FIG. 12B, an embodiment similar to that of FIG. 12A isdepicted, with the exception that traversal of the deployment assemblymay be detected using sensors such as an EKG (electrocardiogram)electrode or a proximity/contact sensor, such as an ultrasoundtransducer and analysis system and/or an OCT fiber and signal processingsystem (158). In another embodiment such as that described in referenceto FIG. 4D, another EKG-signal related sensor coupled to a distalportion of the needle may be utilized to detect initial contact of theneedle and heart wall.

Referring to FIG. 12C, an embodiment similar to that of FIG. 12A isdepicted, with the exception that after crossing the subject tissuestructure with an elongate guiding member (142), a dilator and othertools are advanced into place and utilized (160, 162) before deploymentof any compound helical sutures through advancement of pertinent helicalmembers/sutures/anchors (164) and withdrawal (166) of the helicalmembers to leave the sutures and anchors behind. With one or morecompound helical sutures and anchor elements in place, the tools may bewithdrawn, and an incremental tightening/closure effected (168),followed by completion of the closure and fixation of the pertinentproximal suture ends (156).

Referring to FIG. 13, localized length storage of suture material (52)relative to a needle structure (28, 32, 66) may be facilitated whereinthe needle structure (28, 32, 66) defines a channel into which thesuture material (52) may be fitted during deployment; preferable the fitwith such channel is loose enough that the suture material (52) willdeploy (184) easily out of the channel as the needle structure (28, 32,66) is withdrawn.

Various suture (52) materials may be utilized in accordance with thesubject invention, including resorbable and nonresorbable polymericsutures, woven sutures, highly stretchable sutures (the “stretch” ofwhich may be utilized to facilitate localized length storagefunctionality), and metallic sutures or suture-like structures, such asfine gauge nitinol wire configured to form a compound helix as describedabove. Referring to FIG. 14, a sawtooth pattern of a suture (52) may beutilized for localized length storage functionality in relation to aneedle device (32). In the depicted embodiment, after insertion, aproximal tag (188) coupled to a removable coupling member (186) thattemporarily holds a “zig zag” or “sawtooth” suture length storagepattern in place may be pulled (190), allowing the suture (52) touncouple from the needle (32), akin to the unfurling action of theaforementioned compound helical configurations.

Referring to FIGS. 15A-20, various aspects of additional embodiments ofhelical needle configurations for effecting suture-based closureprocedures are illustrated. FIGS. 15A-16 illustrate aspects of aconfiguration wherein a single helical needle member may be utilized toadvance a suture, and wherein a 1-way tension retainer may be separatedfrom a deployment assembly to become a suture-tension-retainingprosthesis against the outside of the subject tissue structure. FIGS.17A-18 illustrate aspects of a configuration wherein a twin helicalneedle configuration may be utilized to advance two suture members, andwherein a pair of implantable controllably-locking tension retainers maybe used in concert with a pair of load-spreading engagement members toretain tension and/or positioning of the suture members in situ. FIGS.19A-20 illustrate aspects of a configuration wherein a twin helicalneedle configuration may be utilized to advance two suture members, andwherein a pair of implantable 2-way/1-way controllably-advanceabletension retainers may be used in concert with a pair of thrombogenicmembers to retain tension and facilitate biological fixation of thesuture members in situ.

Referring to FIG. 15A, an assembly is depicted for deploying a singlesuture member (52) with a distally affixed anchor member (54) coupled toa helical needle member (66) in manner similar to those described above,with the exception that the proximal portion of the suture member (52)is configured to lead away from the proximal end of the exposed helicalneedle member (66), into an implantable 1-way tension retainer (200),through a tubular elongate tensioning element (16) removably housedwithin a slot formed in the elongate deployment member (14), and to amanual tensioning interface (18), such as the small finger handleconfiguration shown in FIG. 15A. Referring to FIG. 15B, a close-up viewof the configuration of FIG. 15A is shown to further illustrate therelationship of the suture member (52) to the tubular elongatetensioning element (16) and implantable 1-way tension retainer (200),both of which are temporarily and removably housed within portions ofthe elongate deployment member (14). The distal portion of the suturemember (52) is shown in a compound helical configuration (i.e., thesuture member 52 is helically wrapped around a helical needle member66), but as described above, this suture may also be deployed in asingle helical configuration, wherein the distal suture member (52)portion is simply aligned with the helical winds of the helical needlemember (for example, using a suture-retaining slot formed in the helicalneedle member 66) to form a single helical suture pattern very similarto the helical pattern of the helical needle member (66). Forillustrative purposes, compound helical configurations are shown in theembodiments of FIGS. 15A-15J, 17A-17F, and 19A-19Z-8.

Referring again to FIG. 15B, after the helical needle member (66) andassociated anchor member (54) and distal portion of the suture member(52) have been driven at least part of the way across the subject tissuestructure, as described above, the deployment member (14) may be backedoff in a reverse rotational direction to leave behind the anchor member(54) and distal portion of the suture member (52). When ultimate closureof the associated wound is desired, an assembly comprising the manualtensioning interface (18), elongate tensioning element (16), andimplantable 1-way tension retainer (200) may be manually separated awayfrom the handle-like body of the elongate deployment member, and themanual tensioning interface (18) may be pulled relative to the somewhatflexible, yet somewhat stiff in column compression tubular structure ofthe elongate tensioning element (16) to push the implantable 1-waytension retainer (200) down the suture distally toward the exposed outerwall of the subject tissue structure where it may be cinched into placeand left to retain tension on the implanted portion of the suture member(52), after which the elongate tensioning element (16) and manualtensioning interface (18) maybe removed away proximally so that anyremaining proximal ends of the suture member (52) may be clipped or tiedoff, similar to the scenario described above in reference to FIGS. 4Nand 4O.

FIGS. 15C through 15J illustrate some of the complexities of the 1-waytension retainer (200) and its association with the helical needlemember (66), elongate deployment member (14), and suture member (52).Referring to FIG. 15C, the elongate tensioning element (item 16 of FIG.15B) has been removed to show the pathway of the suture element (52)proximal of the 1-way tension retainer (200), as well as an additionallooped tension element (202) configured to assist with the applicationof compressive loads to the elongate tensioning element (item 16 of FIG.15B). FIG. 15D shows an end view depicting the same structure as shownin FIG. 15C, to illustrate the pathways of the suture member (52) andadditional looped tension element (202). Referring to FIGS. 15E and 15F,two different views of a 1-way tension retainer (200) are shown alongwith an associated suture member (52). As shown in FIG. 15E, the 1-waytension retainer (200) comprises an assembly of a housing and a movabledoor member (204) configured to hinge about a pivot. With the suturemember (52) threaded around the door member (204) in a pattern asillustrated in a close up and partial views of FIGS. 15G-15J, theconfiguration allows for the suture member to be pulled tight in onedirection, but not in the other direction, because the other directioncauses the door to pivot down into a clamping configuration versus oneportion of the suture member (52) such that the suture member becomesimmobile relative to the door member (204) or housing (206). In oneembodiment, the door member (204) may be biased to close against thehousing (206) with a spring, such as a cantilever or coil type spring,such that a level of compression is always applied upon the portion ofthe suture member (52) passing through the interface of the door member(204) and housing (206). In other words, in such a configuration, thedoor member (204) and housing (206) may be biased to clamp down upon thesuture member (52).

Referring to FIG. 16, a process for utilizing technology such as thatdepicted in FIGS. 15A-15J is illustrated. As shown in FIG. 16, afterpreoperative diagnostics and patient preparation (138), access may becreated (140) to the subject tissue structure (for example, athoracotomy may be created to access the wall of the heart, the heartwall being the subject of the subsequent wall crossing and closure). Thesubject tissue structure may be at least partially crossed (142) usingan elongate guiding member such as a needle, which may be navigatedutilizing various imaging, sensing, and/or navigation modalities. Theneedle may be followed by a guidewire (i.e., a guidewire advancedthrough the needle). One or more helical needle/suture assemblies may beadvanced (144) across a portion of the tissue wall following theelongate guiding member (or in another embodiment, without the assistantof a guiding member); depth of positioning (145) of one or more of thepertinent structures (such as the distal needle tips, anchor memberpositions, or the like) may be monitored (using an aperture 220 andassociated lumen such as that described below in reference to FIG.17B—or a pressure transducer configured to sense pressure at a chosendistal location, the transducer preferably operatively coupled to ameans for signaling an operator, such as a small proximally-positionedlight that toggles between red and green colors when the given pressurethreshold for completed insertion/deployment has been reached); withfull insertion/deployment completed, the helical member may be axiallyand rotationally withdrawn to place an anchoring element and compoundhelical suture into a configuration wherein they may be subsequentlyutilized to effect a closure (146), and such configuration may beconfirmed (148) before further interventional steps. Subsequent toconfirmation that a closure configuration appears to be ready, a dilator(150) and/or other tools (152) may be advanced through the suture helix,thereby expanding the suture helix so that pertinent diagnostic and/orinterventional steps may be accomplished, such as the installation of aheart valve. Subsequently, the dilator may be re-inserted (i.e., using ahemostatically-valved sheath) in place of the diagnostic and/orinterventional tools (208), and the tapered outer shape of the dilatormay be utilized to effect an incremental tightening of the wound orport, using, for example, one or more 1-way tension retainers (200). Aguidewire may be left in place as a “test closure” is accomplishedaround the guidewire to permit observation of the intervention whilealso permitting easy re-access. The closure may be completed with fullwithdrawal of the dilator, needle, and guidewire, tightening of the oneor more 1-way tension retainers (200), and proximal fixation of thesuture end or ends to retain tension (210).

Referring to FIGS. 17A-20, another embodiment is shown wherein a twoneedle (66, 67) configuration may be utilized to simultaneously inserttwo suture members and two associated anchor members. The assemblydepicted in FIG. 17A includes a sleeve (212) slidably coupled over theelongate delivery member (16). The sleeve (212) may be freely rotatableand longitudinally slidable to assist with atraumatic interfacing of theinstrumentation versus nearby tissue structures such as a chest wallwound and nearby calcified tissue. A manual tensioning interface (18) iscoupled to the proximal end of one or more of the suture members, and atouhy assembly (214) may be configured to allow for valved switching oftools and elongate members, such as a guidewire and various catheters. Arelatively large surface engagement member (216) is configured to beurged against the subject tissue wall between the tissue and a suturetensioning structure, such as a 1-way tension retainer as describedabove in reference to FIGS. 15A-16, or such as the controllably-lockingtension retainer (218) shown in greater detail in FIGS. 17B-17F.

Referring to the close-up orthogonal view of FIG. 17B, the relativelyflat engagement member (216) and controllably-locking tension retainer(218) are shown, along with an aperture (220) which may be present inany of the aforementioned or depicted variations of the elongatetracking member (68). The aperture may be fluidly coupled to a lumendown the center of the elongate tracking member, and such lumen maybecome proximally exposed (for example, by a simple exit from thedeployment member 14, or via exposure to a window within the deploymentmember 14 or other associated member, the window being configured toassist an operator in visualizing blood or other fluid that may bleedback through the lumen, indicating that the aperture has been exposed tosuch relatively high pressure fluid), so that an operator can see ifblood or other pressurized fluids are coming through the aperture andthrough the lumen, as a signal that such aperture has been exposed tosuch pressurized fluids. Two or more apertures may be similarly used inthe embodiments depicted here in FIGS. 17A-17F, and also the embodimentsdescribed in reference to FIGS. 19A-19Z-8, with each aperture fluidlyconnected to a lumen, which is connected either to a detection window orlumen for viewing a flash of fluid to which the aperture has beenexposed—or coupled to a sensor configured to detect the fluid immersionof the aperture, such as an OCT sensor, an ultrasound sensor, an RFimpedance sensor, a partial pressure of oxygen sensor, and/or a pressuresensor. One or more apertures and/or sensors may be geometrically keyedto (i.e., configured to indicate protrusion to the level of): the distalend of a helical needle member, the distal end of an anchor member, theproximal end of an anchor member (i.e., to confirm that the anchor has,for example, crossed a threshold of a distal tissue wall). In oneembodiment, for example, the aperture (220) may be longitudinallypositioned more distally along the elongate tracking member (68)relative to the longitudinal positions of the distal ends of the needlemembers (66, 67) to provide an operator with a clear indication that theneedle ends are a known distance from pressurized fluid on the otherside of the subject tissue wall. In another embodiment, such as thatdepicted in FIG. 17B, the aperture (220) may be positioned with a knowndistance proximal to the distal ends of the needle members (66, 67) toprovide a signal to an operator that the distal ends of the needlemembers (66, 67) and associated anchor members should be past thethreshold of the recently crossed tissue structure wall, and havereached pressurized fluid on the other side of the wall (i.e., such asin the case of crossing a heart wall into one of the cavities of theheart). In another embodiment, multiple apertures may be present tosignal various things to an operator. For example, in one embodiment, asmall aperture may be positioned most distally to signal that a firstlongitudinal position of the elongate tracking member and associatedneedle complex (66, 67) has been achieved, while a larger aperture(providing a noticeably larger flow rate proximally observed by theuser) may be located at another known and more proximal location asanother signal to the user. In another embodiment, two or more aperturesmay be associated with two or more unique lumens to provide clear anddistinguished signaling.

Referring to FIG. 17C, the movable sleeve member has been removed tomore clearly show the elongate deployment member (16) as it is coupledto a lock actuation member housing (222) and a suture conduit housing(228). In the depicted embodiment, both of these housings (222, 228) aredistally coupled to a lock actuation distal housing shoe (226) which iscoupled to the controllably-locking tension retainer (218). Referring toFIG. 17D, the controllably-locking tension retainer (218) is positionedadjacent the engagement member (216), which may comprise a thrombogenicmaterial to function somewhat like a surgical pledget to spread outloads and promote clotting and tissue encapsulation. Referring to FIG.17E, the lock actuation housing shoe (226 in FIG. 17D) has been removedto reveal the interfacing (234) of the threaded distal portion of thelock actuation member (230) with the controllably-locking tensionretainer (218). A simplified orthogonal view is shown in FIG. 17F toillustrate that a length of suture may be passed freely through the slot(232) in the spring-biased (i.e., biased to close and thereby close theslot) tension retainer (218) until the lock actuation member (230) isthreaded out (i.e., by manually threading it out using a proximalmanipulation interface placed proximal of the proximal end of the lockactuation member housing (222) (see, for example, FIG. 17C)), afterwhich the close closes upon the captured suture portion, causing alocking of the suture relative to the tension retainer (218). Thus, inoperation, the suture member may be proximally tightened using themanual interface (18), after which the lock actuation member (230) maybe threaded out to capture a portion of the suture in the slot (232),thereby locking the tension retainer (218) in place, presumably in aconfiguration wherein it will apply a load to be spread on the nearbytissue structure by the engagement member (216).

In another embodiment, an active compression locking configuration maybe used to allow both relative slideability between the lockingconfiguration and interfaced suture material, and conversion (i.e.,subsequent to application of a load) to a fixed relationship whereinrelative motion is not allowed. In one embodiment, such an activecompression locking configuration may comprise a coupled assembly of twoportions that may be compressed against each other to convert to a fixedrelationship (i.e., akin to a “split shot” that may be moved or slidalong a suture line, then clamped into a fastened position relative tothe suture line with a pliers or the like). In another embodiment, twomovably coupled—or decoupled—members may be compressed or otherwiseloaded together (for example, with a crimping tool) to convert from arelative movement configuration between the fastener and suture line, toa clamped configuration that disallows relative motion. Certain medicalgrade type crimping fasteners are available from the orthopaedicsdivision of Smith & Nephew, Inc., of Memphis, Tenn.

Referring to FIG. 18, a process for utilizing technology such as thatdepicted in FIGS. 17A-17F is illustrated. As shown in FIG. 18, afterpreoperative diagnostics and patient preparation (138), access may becreated (140) to the subject tissue structure (for example, athoracotomy may be created to access the wall of the heart, the heartwall being the subject of the subsequent wall crossing and closure). Thesubject tissue structure may be at least partially crossed (142) usingan elongate guiding member such as a needle, which may be navigatedutilizing various imaging, sensing, and/or navigation modalities. Theneedle may be followed by a guidewire (i.e., a guidewire advancedthrough the needle). One or more helical needle/suture assemblies may beadvanced (144) across a portion of the tissue wall following theelongate guiding member (or in another embodiment, without the assistantof a guiding member); depth of positioning (145) of one or more of thepertinent structures (such as the distal needle tips, anchor memberpositions, or the like) may be monitored (using an aperture 220 andassociated lumen such as that described above in reference to FIG.17B—or a pressure transducer configured to sense pressure at a chosendistal location, the transducer preferably operatively coupled to ameans for signaling an operator, such as a small proximally-positionedlight that toggles between red and green colors when the given pressurethreshold for completed insertion/deployment has been reached); withfull insertion/deployment completed, the helical member may be axiallyand rotationally withdrawn to place an anchoring element and compoundhelical suture into a configuration wherein they may be subsequentlyutilized to effect a closure (146), and such configuration may beconfirmed (148) before further interventional steps. Subsequent toconfirmation that a closure configuration appears to be ready, a dilator(150) and/or other tools (152) may be advanced through the suture helix,thereby expanding the suture helix so that pertinent diagnostic and/orinterventional steps may be accomplished, such as the installation of aheart valve. Subsequently, the dilator may be re-inserted (i.e., using ahemostatically-valved sheath) in place of the diagnostic and/orinterventional tools (236), and the tapered outer shape of the dilatormay be utilized to effect an incremental tightening of the wound orport, using, for example, one or more controllably locking tensionretainers (218). A guidewire may be left in place as a “test closure” isaccomplished around the guidewire to permit observation of theintervention while also permitting easy re-access. The closure may becompleted with full withdrawal of the dilator, needle, and guidewire,tightening of the one or more controllably locking tension retainers(218), and proximal fixation of the suture end or ends to retain tension(238).

Referring to FIGS. 19A-20, various aspects of another embodiment forutilizing a twin helical needle (66, 67) configuration to install two ormore suture members (52, 53) with anchors (54, 55) are depicted. Theassembly of FIG. 19A includes a proximal housing assembly (240)configured to be comfortably handled and/or held in place by an operatorwhile a manual rotation interface (244) is turned clockwise orcounterclockwise (with the other available hand, for example) to advancea coupling member (246) coupled to one or more (in the depictedembodiment a pair of two) helical needle members carrying suture andanchor elements. The proximal portion of the coupling member (246) mayhave slots or threads (248) formed therein that are configured tomechanically and movably interface with one or more pins (252). Thecoupling member (246) is configured to advance or retract relative tothe proximal housing assembly (240) in response to rotation of themanual rotation interface (244) coupled to the coupling member (246). Adistal housing, or sleeve member, (242) guides the distal portion of thecoupling member (246), provides a mechanical platform for a specializedend geometry (as described below), and provides a platform for storingadditional suture length locally (also as described below). The couplingmember (246) may comprise one or more graduation marks (250) toestablish how far the coupling member (246) has been inserted relativeto the proximal housing assembly (240). In one embodiment, suchgraduation marks may be utilized as indicators that the needle members(66, 67) have been inserted into the subject tissue wall by a distanceequivalent to the typical thickness of a heart wall, or by some otherpredetermined amount.

Referring to FIG. 19B, a different orthogonal view is illustrated toshow that the assembly comprises two suture members (52, 53) and twoassociated suture tensioning assemblies (254, 255) that may be removablycoupled to the proximal housing assembly (240). In the depictedembodiment, they (254, 255) are configured to temporarily reside withinslots or recesses formed within the proximal housing assembly (240).

Referring to FIG. 19C, an orthogonal view of the distal end of theassembly of FIG. 19A or 19B is shown to illustrate a distal interfacemember (256) that comprises one or more ramp members (258, 260)configured to locally stretch and reorient tissue that is encounterednear the distal tips of the needle members (66, 67), to facilitatecapture of such tissue by such needle tips, as opposed to laceration ofthe tissue when the needle tips are dragged along without capturing,puncturing, and protruding into such tissue. In other words, these rampmembers locally increase the angle of approach of the needle tips versusthe tissue to increase the odds of capture, puncture, and protrusion ofthe needle tips into the tissue without laceration or scarification. Thedepicted embodiment shows two ramp members on each side of the needlemember (66, 67) tip such that each needle member (66, 67) tip is nearlyencapsulated by the associated pair of ramp members (258, 260). Inanother embodiment, only one ramp member may be used for the samefunction adjacent each needle member (66, 67). In use, an operator maymanually grasp the proximal (240) and/or distal housing, or sleevemember, (242), push the distal interface member (256) against thetargeted tissue structure—thus causing the ramp members (258, 260) toengage, locally stretch, and locally reorient nearby tissue structuresubportions, and turn the coupling member (246) with the manual rotationinterface (244) to advance the helical needle members (66, 67) and theassociated anchors (118, 120; or 54, 55, etc) and suture members (52,53) into the targeted tissue structure in a predictable format.

Also shown in the close-up views of FIGS. 19C and 19D is the proximalextension of the suture members (52, 54) from the associated anchormembers (118, 120) into a local suture length storage membrane orreservoir (262).

Referring to FIG. 19D, each of the ramp member pairs (260) may also bereferred to as an indentor member comprising one or more distallyprotruding shape features (in this embodiment the distally protrudingshape features are two ramp members; also viewable as one ramp memberthat is bisected by the emerging helical needles and associated anchormembers). These distally protruding shape features are configured toconcentrate interfacial stresses upon the tissue structure such that theportions of the tissue structure that are adjacent to the distal ends ofthe needle/anchor assemblies become locally strained about the distallyprotruding shape features as these shape features are advanced intocontact with the adjacent tissue structure portions. It is this contactconfiguration that locally increases the effective angle of penetrationbetween the anchor/needle assemblies and the tissue structure. Variousembodiments may include one or more distally protruding shape featuresor surfaces that comprise portions of a spherical surface, a linear rampsurface (as shown in FIG. 19D, for example, wherein the ramping up alongeach ramp is substantially linear), an arcuate or nonlinear ramp surface(wherein the ramping is nonlinear), or a single or multiple stepped rampsurface (wherein the ramping comprises discrete steps). The rampingangle in the depicted embodiment is generally parallel to the angleformed as the helical needle and associated anchor emerge from thedistal interface member (256), but in other embodiments these geometriesmay not match. The non-ramped aspect of the depicted embodimentcomprises a substantially perpendicular leading surface (i.e.,perpendicular to the surface of the distal interface member (256) andgenerally aligned with a longitudinal axis of the helical needleassembly. The depicted ramp members are bisected by the needle members;in another embodiment, the needle members emerge adjacent to, but notdirectly through the middle of, the ramp members or other protrudingshape features. The shape features in the embodiment of FIG. 19D arehelical wrapped about approximately the same longitudinal axis as thehelical member. In other embodiments, they may be wrapped about adifferent axis. As described below in reference to FIG. 23B, thedistally protruding shape features may comprise one or more tissuetraction features (such as the barbed features 324 depicted in FIG. 23B)configured to prevent relative motion between the distally protrudingshape feature and portions of the tissue structure with which it may bedirectly interfaced.

Referring to FIG. 19E, this membrane (262) has a slot or cut definedtherein that allows additional suture length to be pulled out of therelatively flat membrane reservoir (262), which may be configuredinitially to contain a few additional loops worth (264) of length ofsuture material (52). For example, in one embodiment, a local suturelength enclosure, such as one comprising a membrane material with one ormore access apertures or slots for the suture member to be drawn out andtensioned proximally, may have one or more loops of suture providing anadditional length of between about 20 millimeters and about 500millimeters that may be pulled out, for example, under tensile loadingfrom associated anchor and helical members advancing into a tissuestructure relative to the location of the reservoir, which is generallyconfigured to somewhat fixed relative to the position of the proximalwall of the tissue structure in one embodiment. Thus the suture iscoupled distally to an anchor member (118, 120), then is routed throughthe membrane reservoir (262), into a slot in the proximal housing member(240) to enter a suture tensioning assembly (254, 255), the subportionsof which are described below. A different orthogonal view of theassembly of FIG. 19E is shown in FIG. 19F. A close view of one of themembrane reservoirs (262) and associated suture member (52) pathways isdepicted in FIG. 19G.

Referring to FIGS. 19H and 19X, with the proximal housing member (240)hidden away, the suture tensioning assemblies (254, 255) are moreclearly visible. FIG. 19X also has the distal housing member, or sleevemember, (242) hidden to show the underlying coupling member (246)extending distally to a sleeved (294) coupling with the helical needlemembers (66, 67), which are configured to rotatably extend out of theapertures in the distal interface member (256), through the ramp members(258, 260) as described above.

Referring back to FIGS. 19I-19W, aspects of and operation of the suturetensioning assemblies (254, 255) are depicted. Referring to FIG. 19I, asuture tensioning assembly is shown comprising a manual tensioninginterface (18) coupled to a distal end of the suture member (52). Thesuture member extends distally from the manual tensioning interface(18), around a length storage and fixation spool fitting (272), througha lumen formed in a small handle member (268), into a lumen formedthrough the tubular suture tensioning element (16), through a lockingmember shoe housing (266) coupled to the distal end of the tubularsuture tensioning element (16), into a two-way/one-way controllablyadvanceable tension retainer (265), and out toward the membranereservoir (not shown in FIG. 19I; element 262 in FIG. 19H, for example).

FIGS. 19J-19L show three different orthogonal views of the sametwo-way/one-way controllably advanceable tension retainer (265)assembly, which comprises a main housing member (280), a door member(278) rotatably coupled to the main housing member (280), a spring (276)configured to bias the door member (278) closed against the main mousingmember (280), as in FIGS. 19J-19L. The suture member (52) is routedthrough an alignment aperture (282) in the door member (278) such thatit is caught, or “grasped”, between the closed door member (278) and theassociated surface of the main housing member (280). The bottom of thetension retainer (265) assembly may be coupled to a pad (274) which maybe configured to de-concentrate interfacial loads between the bottomsurface of the main housing member (280) and nearby tissue structuresagainst which the main housing member (280) may be advanced by virtue ofsuture member (52) tightening. The pad (274) may comprise a materialsuch as Dacron®, or a nonthrombogenic material treated with athrombogenic chemical agent or medicine, to assist with clot formationand biological fixation and incorporation. As shown in FIGS. 19M-19O, anactuation member (284) may be temporarily threaded into the door member(278) to urge (i.e., against the spring 276 load biasing the door memberto shut) the door member (278) open relative to the main housing member(280), thus leaving the suture member (52) relatively unconstrained andfree to move in both directions relative to the main housing member(280). By backing out (i.e., by threading out in reverse) the actuationmember (284), the door becomes unconstrained by the actuation member,and is urged shut by the spring (276), thus capturing the suture member(52) between the door member (278) and the main housing member (280).With the door member (278) shut, the suture member (52) may still bepulled in an upward (i.e., toward the top of the illustration pagecontaining FIGS. 19M-19O) to cause further tensioning of the assemblyagainst a subject tissue structure wall, because this 1-way directionaltensioning urges the door to slightly open and allow motion of thesuture member (52) relative to the door member (278) and main housingmember (280); on the contrary, tension downward on the suture memberwhen the door member (278) is shut against the suture member (52) onlycauses the door to shut even tighter, by virtue of the cam-like geometryof the interface between the door member (278) and suture member (52),as shown, for example, in FIGS. 19N and 19O. Thus, the assembly iscontrollably switchable: from a state of two-way movability of suture(52) relative to locking member (265), to a state of one-way movability(i.e., tightening only) of the suture (52) relative to locking member(265)—and this switching from one mode to another mode is conducted bythreading in the actuation member (284) to essentially jack open thedoor to temporarily have the two-way movability mode. Referring to FIGS.19P and 19Q, an experimental loading configuration and data relatedthereto are illustrated. FIG. 19Q features two plots (290, 292) of pullforce (286) versus suture displacement (288) to show that the thetwo-way/one-way switchable locking member is capable of holdingsignificant loads when in the one-way mode with the door member (278) ina shut position against the subject suture member (52).

Referring to FIG. 19R, the various portions of the suture tensioningassembly embodiment are shown in a somewhat deconstructed view. In anassembled configuration, the actuation member (284) may be insertedthrough a lumen formed by the tubular tensioning element (16) andtwisted (i.e., using a proximal manual gripping interface 270) to threadthe distal portion of the actuation member (284) into the door member(278) of the two-way/one-way controllably advanceable locking member(265). FIGS. 19S and 19T show close-up views of the interaction of theproximal portions of the suture member (52) with the spool member (272).FIGS. 19U-19W show other orthogonal views of various states of assemblyof the subject suture tensioning assembly (254, 255) embodiment. FIG.19Y-19Z-1 illustrate various orthogonal views of partial assemblies ofthe distal end of the subject access and closure instrument to show thepositions of the needle members (66, 67), suture members (52, 53),distal interface (256), suture length storage membranes (262, 263), andelongate tracking member (68) aperture (220) relative to each other.

In one embodiment, the spool member (272) may be utilized to transientlylock down a given length of suture into a tensile state, andsubsequently to adjust the length to establish a different tensilestate. For example, during a process such as that described above inreference to FIG. 12A (element 154 in particular) wherein a dilator orother member is incrementally withdrawn as the one or more sutures areincrementally tightened, the spool member (272) may be utilized totemporarily retain various tensile states during such a process. Inanother embodiment, a releasable pinching clamp may be utilized to havethe same function as described herein for the spool member (i.e., totemporarily retain a given tensile state, while also providingrelatively easy releasability for repositioning).

Referring to FIGS. 19Z-2 and 19Z-3, two embodiments of anchor members(296, 298) are depicted. The embodiment in FIG. 19Z-2 may be createdfrom a single piece of tubing using, for example, a laser cutter. Aneyelet or suture fastening interface (302) comprises a cut-out portion,as does a tail (300), which is configured to rotate the anchor (296) andgrab onto nearby tissues when a suture coupled to the eyelet is pulledfrom a direction toward the tail (300)—somewhat akin to the action of atoggle bolt. FIG. 19 z-3 depicts a machined version of a similarstructure, created from two parts in one embodiment (the tail 304 beinga separate part that is fused with the body); the eyelet (306) may bemachined. Either embodiment may have a tapered forward geometry (308,310), formed, for example, by laser cutting or grinding.

Referring to FIGS. 19Z-4 to 19Z-8, in use, an assembly such as thatdepicted in FIG. 19A may be advanced against a targeted tissue structurewall, and when in an appropriate position, the positioning of theproximal and distal housing members (240, 242) may be maintained whilethe manual rotation interface (244) is utilized to rotate the needlemembers (66, 67) distally out through the distal interface member (256)and into the subject tissue wall (not shown), along with the elongatetracking member (68), which, as described above, may assist inpreventing “walking” of the needles relative to the targeted portion ofthe tissue wall, and/or undesirable localized overstraining of thenearby tissue. FIG. 19Z-5 shows a close up view of the needles extendedout through the distal interface member into what could be a targetedtissue structure, the needles carrying two machined anchor members (298,299) which may be coupled to two suture members (not shown). Asdescribed above, one or more apertures or sensors on various portions ofthe distal hardware, along with one or more graduation marks (250) onthe proximal coupling member (246) hardware, may assist in providing anoperator with precision feedback as to how many turns have been madewith the manual rotation interface (244), and how deep the distalhardware is into the nearby tissue. Referring to FIG. 19Z-7, with anadequate depth of anchor members and associated suture members achieved,the main bulk of the instrument assembly may be removed by reversing outthe helical needle members and withdrawing the proximal instrumenthousings (240) and associated hardware—while the suture tensioningassemblies (254, 255) are decoupled from such proximal instrumenthousings (240) and associated hardware, as shown in FIG. 19Z-7, to leavebehind only the anchors, sutures, and suture tensioning assemblies (254,255). The sutures (52, 53) may be tightened onto the tissue structureusing the associated locking members (such as two-way/one-waycontrollably advanceable locking members described above), tubulartensioning elements (16), and tensioning of the manual tensioninginterfaces (18).

Referring to FIG. 20, a process for utilizing technology such as thatdepicted in FIGS. 19A-19Z-8 is illustrated. As shown in FIG. 20, afterpreoperative diagnostics and patient preparation (138), access may becreated (140) to the subject tissue structure (for example, athoracotomy may be created to access the wall of the heart, the heartwall being the subject of the subsequent wall crossing and closure). Thesubject tissue structure may be at least partially crossed (142) usingan elongate guiding member such as a needle, which may be navigatedutilizing various imaging, sensing, and/or navigation modalities. Theneedle may be followed by a guidewire (i.e., a guidewire advancedthrough the needle). One or more helical needle/suture assemblies may beadvanced (144) across a portion of the tissue wall following theelongate guiding member (or in another embodiment, without the assistantof a guiding member); depth of positioning (145) of one or more of thepertinent structures (such as the distal needle tips, anchor memberpositions, or the like) may be monitored (using an aperture 220 andassociated lumen such as that described above in reference to FIG.17B—or a pressure transducer configured to sense pressure at a chosendistal location, the transducer preferably operatively coupled to ameans for signaling an operator, such as a small proximally-positionedlight that toggles between red and green colors when the given pressurethreshold for completed insertion/deployment has been reached); withfull insertion/deployment completed, the helical member may be axiallyand rotationally withdrawn to place an anchoring element and compoundhelical suture into a configuration wherein they may be subsequentlyutilized to effect a closure (146), and such configuration may beconfirmed (148) before further interventional steps. Subsequent toconfirmation that a closure configuration appears to be ready, a dilator(150) and/or other tools (152) may be advanced through the suture helix,thereby expanding the suture helix so that pertinent diagnostic and/orinterventional steps may be accomplished, such as the installation of aheart valve. Subsequently, the dilator may be re-inserted (i.e., using ahemostatically-valved sheath) in place of the diagnostic and/orinterventional tools (312), and the tapered outer shape of the dilatormay be utilized to effect an incremental tightening of the wound orport, using, for example, one or more controllably lockingtwo-way/one-way tension retainers (265). A guidewire may be left inplace as a “test closure” is accomplished around the guidewire to permitobservation of the intervention while also permitting easy re-access.The closure may be completed with full withdrawal of the dilator,needle, and guidewire, tightening of the one or more controllablylocking two-way/one-way tension retainers (265), and proximal fixationof the suture end or ends to retain tension (314).

In the aforementioned illustrations and examples, one or more helicalneedle members have been discussed. We have discovered that there arevarious important relationships involved in selecting an optimal helicalneedle member and suture configuration. For example, referring to FIG.21, we have shown that a very slight angle of approach (316), i.e., witha needle member tip only a few degrees from a tangential relationshiprelative to a point of entry into a targeted tissue structure (48) (inthe depicted configuration, the angle of approach 316 is about 15degrees) may result in some amount of relative motion between the tissuestructure (48) and needle member (66) tip before the tip actually divesacross the surface of the tissue structure (48). Such relative motiongenerally is not desirable, as it may result in relative motion andpossible undesirable loading between the pericardium, epicardium, suturemember, and needle member. Referring to FIG. 22, with a helical needlemember (66) having the same helical pitch, one or more ramp members(258) may be utilized to locally reorient the tissue structure (48) atthe point of entry of the helical needle member (66), such that theeffective angle of approach (318) resulting from the combination of theramp member (258) reorientation and the orientation of the needle basedupon the associated helical pitch is relatively large (in thisembodiment, about 70 degrees); we have found that such a relativelylarge effective angle of approach generally causes the needle member(66) to dive directly into and across the targeted tissue structure(48), as would be desired. Referring to FIGS. 23A and 23B, in anotherembodiment, the one or more ramp members (258) may be coupled to one ormore traction features (324) (shown best in the close up view of FIG.23B) to further assist in preventing relative sliding motion between thepericardial membrane (320), epicardial surface (322) and aspects of thetool assembly during insertion. In one embodiment, the one or moretraction features (324) comprise one or more barbs or hooklikeprojections from the ramp member (258) surface. In a heart wall crossingscenario, with the deployment assembly pressed against the pericardialmembrane (320) and the elongate tracking member (68) pressed across thepericardial membrane (320) and epicardial surface (322) into the wall ofthe heart, the ramp member (258) assists with locally adjusting thetissue orientation immediately adjacent the helical member (66) point ofentry, as described above, and the one or more traction features pressthrough at least a portion of the pericardial membrane (320)/epicardialsurface (322)/heart wall composite to assist with a clean and relativelyload-free passage of the needle member (66) tip across the pericardialmembrane (320) and epicardial surface (322), and into the wall of theheart. Thus we have created configurations and techniques forsuccessfully advancing one or more helical needle structures into asubstantially slippery and viscoelastic tissue structure.

One of the other challenges in effecting an adequate closure when theprocedure has been completed is assuring that proximal tensioning of theone or more deployed suture members will indeed effect a closure of thewound through the length of the wound. We define a term “helical turn”to represent the number of full turns a suture or needle travels withina subject tissue structure when viewed from a perspective coaxial to theaxis of the helical winding (i.e., one helical turn would be where theneedle and/or suture traveled a pathway that appears to create a full360 degree circle when viewed down the longitudinal axis of the helix;one-half helical turn would appear like a half-circle, or 180 degrees ofarcuate travel around the outer shape of the helix). We have found thatwith myocardial tissue and conventional suture materials, there is anoptimal number of helical turns of deployed suture material; below thisnumber, there is not enough suture helically deployed within the tissuestructure to pull shut the wound; above this number, there is too muchsuture deployed into the tissue structure from a friction perspective,such that pulling proximally on the suture member to tension it andclose the wound only tensions the proximal few helical wraps, and leavesthe distal helical wraps only partially tightened due to the well known“flat belt” power transmission relationship (the ratio of belt typetensions on the tighter side, to those on the more slack side, areequivalent to e to the mu*theta, wherein mu is the friction coefficientand theta is the angle subtended by the contact surface at the pulley)described, for example, athttp://en.wikipedia.org/wiki/Belt_(mechanical), which is incorporated byreference herein in its entirety—and potentially in a configurationwherein an adequate closure may not be created. Again, with myocardialtissue and conventional suture materials, we have found the ideal numberof turns for good closure performance to be between about one-halfhelical turn and about three helical turns, and more preferably betweenabout 1 helical turn and about 2 helical turns.

Another factor coming into play in selecting the instrumentationconfiguration is the notion that the anchor may be left distally withinthe tissue wall, as in the embodiments of FIG. 4N or 7B, or distallypast the opposite margin of the subject tissue wall, as in theembodiment of FIG. 8B. In the latter scenario, there is some slackmaterial left unconstrained with the anchor, while in the formerscenarios, there is no unconstrained slack. With dilation of the helicalconfiguration, slack at both sides assists with the flat belt issue(i.e., in accordance with the aforementioned flat belt relationship, theratio of tensions is equivalent to e to the mu*theta, and if you cuttheta in half, you have cut the force required down by e to thatfactor—quite a significant nonlinear relationship). But note—uponclosure, in most configurations (i.e., absent some means for alsotensioning from the anchor side of the suture member), the operator isstill dealing with a single-sided tensioning flat-belt scenario, andthere is an important desire to effect a solid closure at the end of theprocedure by tensioning only the proximal end.

Thus there is a confluence of factors at play that result in thehardware configuration selection, including but not limited to: 1) giventhe thickness of the wall to be crossed, we want to get between one halfand two and a half helical turns through that thickness, and morepreferably between one and two helical turns; 2) we would prefer to havethe needle dive straight into the tissue structure without significantnon-puncturing motion before entry; this can be complicated by tooshallow an angle of entry; 3) we need to provide enough cross sectionalarea with the helical windings to accommodate the pertinentinterventional hardware, dilation therefore, and helical suture closurethereof without coring out, lacerating, or necrosing the subject tissue;4) we would prefer to use conventional materials for the suture memberand needle members; 5) we will be dealing with a viscoelastic andpotentially nonhomogeneous material (tissue). It is worth noting thatthis challenge is very different from the challenge of helically windinga running stitch along a tissue surface such that the needle tip isconstantly diving and exiting the tissue surface—the flat belt frictionissues there are completely different (i.e., there is no helix of suturematerial that is fully encapsulated by the tissue and thus subject tothe flat belt relationship issues when tensioned). As described above,the second challenge may be addressed with the inventive ramp membersdescribed herein. The remaining challenges may be addressed byprocessing the scenario as shown in FIG. 24.

Referring to FIG. 24, after determination of patient-specificparameters, such as subject tissue wall dimensions, density, andirregularities (328), and examination of other mechanical parameters,such as estimated viscoelastic, frictional, and mechanical modulusproperties of the subject tissue and instrumentation (330), a deploymentconfiguration may be matched to the scenario (332) to address theaforementioned challenges, and the surgery may be executed (334). Heartwalls, for example, may range anywhere from about 8 mm in thickness toabout 25 mm in thickness. For a relatively thick targeted tissuestructure crossing (for example, in the wall of a congestive heartfailure patient with an enlarged heart), a relatively large helix pitchmay be utilized to cross the appropriate thickness and still placebetween about one-half and two and a half helical turns, or morepreferably between about one and two helical turns, of suture in placefor closure. For a relatively thin targeted tissue structure crossing(for example, through a previously infracted area of a ventricle wall ofa heart), a more shallow pitch may be utilized to ensure that enoughhelical turn is placed in the relatively small thickness of the targetedwall tissue to effect a closure. In one embodiment, for a heart wall ofaverage thickness, about 12 mm in wall thickness, a twin helical needleconfiguration comprising two stainless steel needles with a helix pitchof about 8 mm, a helix diameter of about 15 mm, and an angle of entry(not accounting for ramping members) of about 10 degrees based upon thehelical pitch may be utilized to accommodate typical valve replacementinterventional tools and effect a closure. Other useful embodiments forthinner heart wall crossing include a 5 mm helical pitch (6 degree angleof entry not accounting for ramping members); and a 10 mm helical pitch(12 degree angle of entry not accounting for ramping members). For athicker heart wall, a 13 mm pitch provides approximately one to threefull helical loops with an approximate 15 degree angle of entry. Each ofthese embodiments would preferably incorporate one or more rampingmembers to address the angle of entry challenge, as described above.Other embodiments may include varied needle member helix radii (forexample, one 10 mm radius helical needle may be paired with one 20 mmradius helical needle, both needles carrying a suture member and anchormember).

Yet further embodiments may include helical needle members with inner orouter helical diameters that vary or do not vary relative to lengthalong a longitudinal axis through the center of the helical formation(i.e., such as a tapered helix with a varied inner helix diameter),helical needle members with varying, or not varying, pitch relative tolength along the longitudinal axis. Further, helical needle members maybe formed from solid versus tubular members formed into helical shapes,and these helical members may have various cross sectional geometries(i.e., a tubular helical member material may have a generallyhollow-circular cross section, or a hollow square, rectangle,elliptical, or other cross section; a nontubular, or solid, helicalmember material may have a generally circular cross section, or a solidsquare, rectangle, elliptical, or other cross section). All of thesevariables may be utilized to form many permutations and combinations ofsuitable helical members. For example, a nontapered helix may have aconstant helical pitch along its length (say, for example, a pitchbetween about 5 mm and about 20 mm, or more preferably between about 7mm and about 13 mm)—or a variable helical pitch along its length; atapered helix may have a constant helical pitch along its length—or avariable helical pitch along its length. In one embodiment, an innerhelix diameter is between about 5 mm and about 60 mm, and morepreferably between about 10 mm and about 20 mm. In one embodiment, anouter diameter of a wire or tube (tubular or nontubular/solid) used toform a helical member may have an outer diameter of between about 0.5 mmand about 3 mm. The helix may comprise materials such as stainlesssteel, Nitinol alloy, titanium, cobalt chromium, and various polymersand composites.

Further, as depicted in several of the figures associated hereto, two ormore helical needle members may be utilized in various access andclosure embodiments. In one embodiment, each helix may be geometricallymatched to each other in the set, with substantially coaxiallongitudinal axes. In other embodiments, as in the embodiment of FIGS.5A-5D, for example, helical needle members may have different radii.Further helical needle members may have different helical pitches,different materials, different constructs (as discussed above—solidversus tubular, various cross sectional shapes, variable pitches orhelix diameters with length position, etc.).

Referring to FIG. 25, an embodiment similar to that depicted in FIG. 8Ais shown. The embodiment of FIG. 25 features the deployment of extraslack suture length not only available proximally to the deployedhelical suture pattern (which in the depicted embodiment comprises abouttwo full helical loops substantially encapsulated by the midsubstance ofthe tissue structure 48), but also distally (i.e., on the opposite sideof the targeted tissue structure wall 48). As one or more elongate toolsor instruments (102) are passed through the helical suture pattern,slack may be pulled in not only from the proximal side (338), but alsofrom the distal side (336), providing a significant advantage in view ofthe mechanical overconstraint issues described above in reference to the“flat belt” equation. In other words, in certain embodiments wherein itis possible to provide slack distally as well as proximally (340) in theform of localized length storage or simply some additional length (341),such as between about 3 millimeters and about 48 millimeters, provideddistally by advancing the anchor by an additional distance past thethreshold of the subject tissue wall before retracting the needlemember, such extra distal slack can provide an additional advantage inavoiding flat belt overconstraint, and thus subsequently tensioning ofthe helically-deployed suture pattern may be more uniform. A preferredamount of available proximal slack, using some free length of suturemember, a localized length storage structure, or otherwise, is betweenabout 5 millimeters and about 24 millimeters.

Referring to FIG. 26, a technique for effecting an access and closureusing a configuration such as that depicted in FIG. 25 is illustrated.Referring to FIG. 26, after preoperative diagnostics and patientpreparation (138), access may be created (140), and an elongate guidingmember advanced (142). One or more helical needle/suture assemblies maythen be advanced across the targeted tissue structure—and in thisembodiment, across the distal threshold and beyond by a given length,such that there is suture member slack available on both the proximaland distal sides of the tissue structure that may be subsequently pulledin upon expansion of the helical suture pattern (342). The distal slackis created upon withdrawal of the pertinent helical needle, which leavesbehind the associated anchor member with the additional suture memberslack in tow (344). Subsequently an intervention, such as a valvedeployment with or without an introducer type sheath member (i.e.,certain valve deployment systems are configured to be passed through asheath; others are configured to be introduced without a sheath and maybe passed directly through the helical suture pattern; workinginstruments may comprise prosthetic valves, prothetic clips, graspers,dilators, endoscopes, catheters, balloons, occlusion devices, andablation devices, for example), may be conducted and closure effected(346). Preferably the helical needle and suture configuration isselected to accommodate passage of one or more instruments that mayexpand the suture helical configuration diameter by between about 10%and about 35% during the intervention (with collapse back to closurethereafter, using tension on the suture member, which may be incrementalor cyclical, as described in various embodiments above).

Referring to FIG. 27 another access and closure embodiment isillustrated to emphasize that a helical needle configuration may bespecifically selected based on anatomical characteristics, such as thethickness of the desired portion of the tissue structure to be crossed.In other words, given the aforementioned discussions of preferences forbetween about 1 full helical loop and about 3 full helical loops ofsuture to be deployed to effect desired expandability andcontraction/closure properties, the geometry of the helical needlemember may be tailored to provide such functionality in view of theamount of tissue to be crossed and subsequently expanded and thencollapsed to closure. Referring to FIG. 27, preoperative diagnostics andpatient preparation may include measurements and planning regarding thethickness of the targeted tissue structure wall to be crossed in theintervention (348). Images may be captured using, for example,ultrasound, computed tomography (CT), fluoroscopy, magnetic resonanceimaging (MRI), radiography, and/or optical coherence tomography (OCT).In another embodiment, measurements may be taken in-situ (i.e., afteraccess has been created 140) with a measuring probe or needle, such asone configured to provide a proximal signal to an operator that the tiphas reached a blood-filled cavity, wherein a distal aperature is fluidlycoupled to a lumen that leads to a proximal viewing port or window forthe operator to see a flash of blood as an indicator that the aperturehas reached the blood-filled cavity. Further, needles or probes may beoutfitted with one or more ultrasound transducers to provide for in-situlocal imaging and associated measurement. Referring again to FIG. 27,based upon the measured depth of tissue traversal (i.e., how far acrosstissue the anchor is to be deployed), a helical pitch for a helicalneedle may be selected that will place between about 1 and about 3 fullhelical loops of suture into the desired deployment (350). With accesscreated (140) and an elongate guiding member placed (142), one or morehelical needle assemblies may be advanced to place one or more anchorsand associated suture members (144). Upon withdrawal of the needles, thedesired 1 to 3 helical loops of suture are left to comprise the deployedpattern (352). The suture member deployment may be confirmed, afterwhich various interventional tools may be inserted through the deployedpattern, thereby expanding the pattern and pulling in slack toaccommodate the expansion. After the intervention is completed, thetools may be withdrawn, and the closure effected by tensioning the oneor more suture members (346).

Referring to FIGS. 28A-28D, it may be desirable to transiently providetension on one or more suture members, and to subsequently release thetemporary tension in favor or more permanent tensioning, such as througha two-way/one-way controllably advanceable locking member (265), asdiscussed above. To provide temporary tension fixation before switchingsuch a locking member (265) from a two-way configuration to a one-wayconfiguration, it may be desirable to provide a pinch clamp (354), suchas that depicted in FIG. 28A, or a suture member reel mechanism (362),such as that depicted in FIG. 28B. In other words, it may be desirableduring the closure portion of a procedure to temporarily (i.e., with theability to remove tension or adjust the tensioning position) tension thesuture member without committing to the more permanent tensioningprovided by switching a two-way/one-way controllably advanceable lockingmember (265) from two-way suture movement to one-way only suturemovement (i.e., by operating an actuation member 284, as describedabove). The pinch clamp (354) may be manually installed by manualmanipulation of the two spring-biased arms (358, 360) which produce apinching load at a loading interface (356). The suture reel mechanism(362) depicted in FIG. 28B may be released with a push of a button (366)after tightening around a reel (364) in a one-way tighteningconfiguration. Referring to FIG. 28C, the temporary tighteningmechanisms (354, 362) are shown temporarily retaining tensions on suturemembers (52, 53) that may be configured as those depicted in FIG. 19Z-8above. Referring to FIG. 28D, a close-up orthogonal view with a partialcross section of a suture reel mechanism (362) is depicted. The suturemember (52) is passed from a location in the tissue structure through alocking member (265) that is mechanically constrained in its open (i.e.,2-way) configuration by an actuation member (284) connected to aproximal control knob (270). To temporarily tighten the distal sutureportion (394), a tension may be applied to the proximal suture portion(396) which causes a ratchet reel (364) to rotate, and the ratchetedouter surface of the ratchet reel to continue to incrementally clickpast a pawl (370) which prevents rotation of the reel in the oppositedirection, along with a suture pinch point (368) where the distalaspects of the reel meets the housing (372). Thus a one-way tighteningis effected with the reel/pawl and pinch point configuration. When anoperator wishes to release the tension or back off the assembly a bit,he can depress the release button (366), which depresses the pawl (370)and allows the reel (364) to rotate in a reverse direction. When anoperator wishes to switch from temporary tensioning to more permanenttensioning, he can use the actuation member knob (270) to operate theactuation member (284) to change the locking member (265) from a two-waysuture movement mode to a one-way-only suture movement mode, asdescribed above.

Referring to FIG. 29, a method featuring several of the abovecharacteristics is illustrated. After preoperative diagnostics andpatient preparation (138), a distal portion of a suture member may beadvanced across at least a portion of a targeted tissue structure (374),as described in reference to other embodiments above. With a suturemember placed in a desired configuration for an intervention andsubsequent closure, a tensioning assembly may be advanced toward thewall of the tissue structure, the assembly comprising a two-way/one-waycontrollably switchable locking assembly configuration, such as thosedescribed above, which may comprise a tensioning member base (i.e., suchas that depicted in FIG. 19K as element 280) having a tissue interfacesurface configured to engage a portion of the tissue structure whencoupled to a suture member that may be threaded through the tensioningmember base and into the tissue structure; a suture clamping member(i.e., such as that depicted in FIG. 19K as element 278) configured tobe switched from a first mode, wherein a suture may be tensioned backand forth through a space defined at least in part by the clampingmember, to a second mode, wherein a suture may only be tensioned in onedirection relative to the suture clamping member; and a mode switchingmember (i.e., such as the actuation member 284 or lock actuation member230 described above) movably coupled to the suture clamping member andconfigured to be operable to switch the suture clamping member from thefirst mode to the second mode (376). The physical relationship betweenthe tensioning assembly, suture member, and tissue structure may bemodulated (i.e., tightened, loosened, etc) by modulating the position ofthe tension member base relative to the suture member and tissuestructure wall (378). The tensioning mode may be switched to the secondmode to permanently proceed toward a final tightening of the suturemember (380). The tissue interfacing surface of the tensioning memberbase may comprise a thrombogenic member as shown, for example, in FIGS.19J and 19 k (element 274), or in another embodiment, a fabric pledgetsock (not shown) may be configured to substantially surround orencapsulate the locking assembly (265) and encourage biointegration ofthe tensioning member base and adjacent portions of the tissuestructure. The sock may comprise a durable polymer selected from thegroup consisting of: polyethylene terepthalate, polyethylene, highdensity polyethylene, polypropylene, polytetrafluoroethylene, expandedpolytetrafluoroethylene, poly(ethylene-co-vinyl acetate), poly(butylmethacrylate), and co-polymers thereof. Alternatively, the sock maycomprise a bioresorbable polymer selected from the group consisting of:polylactic acid, polyglycolic acid, polylactic-co-glycolic acid,polylactic acid-co-caprolactone, poly(block-ethyleneoxide-block-lactide-co-glycolide), polyethylene glycol, polyethyleneoxide, poly(block-ethylene oxide-block-propylene oxide-block-ethyleneoxide), polyvinyl pyrrolidone, polyorthoester, polyanhydride,polyhydroxy valerate, polyhydroxy butyrate, and co-polymers thereof.Alternatively, the sock may comprise a bioresorbable material selectedfrom the group consisting of: porcine collagen matrix, human collagenmatrix, equine collagen fleece, gelatin, polyhyaluronic acid, heparin,poly(glucose), poly(alginic acid), chitin, chitosan, cellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose,carboxymethylcellulose; polylysine, polyglutamic acid, albumin, hydroxyapatite, cortical bone, cancellous bone, trabecular bone, bioceramic,ligament tissue, tendon tissue, dura tissue, fascia tissue, pericardiumtissue, thrombin, and fibrin. The tissue-side interface of the lockingassembly may be configured to be interfaced with various tissue types,as described above, including myocardium or pericardium (in which caseone of the preferred method steps comprises identifying the pericardium,either directly, such as which a probe, optically—as in using visualinspection, or with tools such as ultrasound or OCT; another step mayinclude removing at least a portion of the pericardium if directmyocardial interfacing is desired for the locking assembly).

Referring to FIG. 30, one embodiment of an access and closure techniqueis illustrated to emphasize the use of tissue interface indentors, suchas the aforementioned ramping members, to change the effective localangle of entry between an inserted needle and the subject tissuestructure. Referring to FIG. 30, after preoperative diagnostics andpatient preparation (138), a distal end of a needle insertion assemblymay be advanced against a targeted tissue structure, with one or moretissue indentor members, in the form of protruding shape features (i.e.such as ramps, and various other shapes as described above) providingthe leading mechanical edges for the assembly, these features locallydeforming the interfaced tissue to provide greater effective angles ofpenetration between the needle members and the tissue (382). Given suchconfiguration, the needle members may then be inserted relative to therest of the assembly and into the targeted tissue structure, takingadvantage of the preferred angle of entry (384).

Referring to FIG. 31, one embodiment of an access and closure techniqueis illustrated to emphasize the importance of planning and selecting ahelical needle configuration matched to the tissue geometry to becrossed, as in the embodiment of FIG. 27. Referring to FIG. 31,preoperative diagnostics and patient preparation may be conducted, whichmay include measurements of the tissue geometry using direct techniquesor image capture techniques, as described above in reference to FIG. 27.A guiding member may be installed to a desired guiding depth (386), andusing this guiding member as a positional depth guide, a helical membermay be advanced into the tissue structure, preferably such that betweenabout 1 and about 3 helical loops are deployed (388). The helical membermay then be withdrawn, leaving the suture member pattern in place (390),after which the suture pattern may be expanded and later contracted,such as by tensioning the suture member (392).

It is important to note that while the subject closure technologies andconfigurations have been described and illustrated in the context of atrans-apical wall defect or port closure, and specifically regardingtissue structures such as the walls and apex of the ventricles of theheart, such technologies may be broadly applied to various other tissuestructures wherein a closure following creation or existence of a defectis desired—such as in the gastric mucosa for trans-gastric interventionsof various types (for example, following a trans-gastric access of thegall bladder or a trans-colonic retroperitoneal access), or in theuterus for various gynecological interventions (for example, followingremoval of a fibroid tumor residing in the wall of the uterus). Forexample, the subject invention may be utilized to assist in thedeployment of a prosthesis such as that described in U.S. Pat. No.7,104,949, which is incorporated by reference in its entirety. Thefollowing U.S. patent applications are also incorporated by referenceherein in their entirety: 61/315,795, 61/377,670, and 61/361,365.

Any of the aforementioned deployed structures, including sutures, anchormembers, and ratcheting closure device assembly components, may compriseresorbable materials in addition to the aforementioned nonresorbablematerials—to facilitate combinations and permutations which may becompletely resorbed, leaving behind a biologically healed transapicalaccess wound.

Various exemplary embodiments of the invention are described herein.Reference is made to these examples in a non-limiting sense. They areprovided to illustrate more broadly applicable aspects of the invention.Various changes may be made to the invention described and equivalentsmay be substituted without departing from the true spirit and scope ofthe invention. In addition, many modifications may be made to adapt aparticular situation, material, composition of matter, process, processact(s) or step(s) to the objective(s), spirit or scope of the presentinvention. Further, as will be appreciated by those with skill in theart that each of the individual variations described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentinventions. All such modifications are intended to be within the scopeof claims associated with this disclosure.

Any of the devices described for carrying out the subject interventionsmay be provided in packaged combination for use in executing suchinterventions. These supply “kits” further may include instructions foruse and be packaged in sterile trays or containers as commonly employedfor such purposes.

The invention includes methods that may be performed using the subjectdevices. The methods may comprise the act of providing such a suitabledevice. Such provision may be performed by the end user. In other words,the “providing” act merely requires the end user obtain, access,approach, position, set-up, activate, power-up or otherwise act toprovide the requisite device in the subject method. Methods recitedherein may be carried out in any order of the recited events which islogically possible, as well as in the recited order of events.

Exemplary aspects of the invention, together with details regardingmaterial selection and manufacture have been set forth above. As forother details of the present invention, these may be appreciated inconnection with the above-referenced patents and publications as well asgenerally know or appreciated by those with skill in the art. Forexample, one with skill in the art will appreciate that one or morelubricious coatings (e.g., hydrophilic polymers such aspolyvinylpyrrolidone-based compositions, fluoropolymers such astetrafluoroethylene, hydrophilic gel or silicones) may be used inconnection with various portions of the devices, such as relativelylarge interfacial surfaces of movably coupled parts, if desired, forexample, to facilitate low friction manipulation or advancement of suchobjects relative to other portions of the instrumentation or nearbytissue structures. The same may hold true with respect to method-basedaspects of the invention in terms of additional acts as commonly orlogically employed.

In addition, though the invention has been described in reference toseveral examples optionally incorporating various features, theinvention is not to be limited to that which is described or indicatedas contemplated with respect to each variation of the invention. Variouschanges may be made to the invention described and equivalents (whetherrecited herein or not included for the sake of some brevity) may besubstituted without departing from the true spirit and scope of theinvention. In addition, where a range of values is provided, it isunderstood that every intervening value, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range, is encompassed within the invention.

Also, it is contemplated that any optional feature of the inventivevariations described may be set forth and claimed independently, or incombination with any one or more of the features described herein.Reference to a singular item, includes the possibility that there areplural of the same items present. More specifically, as used herein andin claims associated hereto, the singular forms “a,” “an,” “said,” and“the” include plural referents unless the specifically stated otherwise.In other words, use of the articles allow for “at least one” of thesubject item in the description above as well as claims associated withthis disclosure. It is further noted that such claims may be drafted toexclude any optional element. As such, this statement is intended toserve as antecedent basis for use of such exclusive terminology as“solely,” “only” and the like in connection with the recitation of claimelements, or use of a “negative” limitation.

Without the use of such exclusive terminology, the term “comprising” inclaims associated with this disclosure shall allow for the inclusion ofany additional element—irrespective of whether a given number ofelements are enumerated in such claims, or the addition of a featurecould be regarded as transforming the nature of an element set forth insuch claims. Except as specifically defined herein, all technical andscientific terms used herein are to be given as broad a commonlyunderstood meaning as possible while maintaining claim validity.

The breadth of the present invention is not to be limited to theexamples provided and/or the subject specification, but rather only bythe scope of claim language associated with this disclosure.

The invention claimed is:
 1. A system for advancing a needle into atissue structure, comprising: a. an elongate needle member having atapered distal tip; b. an insertion member having proximal and distalends, the distal end being coupled to the elongate needle member, andthe proximal end being configured to be manipulated by an operator; andc. a tissue interface indentor member coupled to the insertion memberand operatively coupled to the elongate needle member, the tissueinterface indentor member comprising a distally protruding shape featureconfigured to contact one or more portions of the tissue structureadjacent to the distal tip of the elongate needle member and change anavailable angle of penetration between such portions and the distal tipof the elongate needle member as the distal tip is inserted into tissuestructure wherein the distally protruding shape feature and distal tipof the elongate needle member are operatively coupled such that thedistal tip is movably coupled through a portion of the distallyprotruding shape feature.
 2. The system of claim 1, wherein the elongateneedle member comprises a shape selected from the group consisting of: asubstantially straight shape, an arcuate shape, and a helical shape. 3.The system of claim 2, wherein the elongate needle member comprises afirst helical member that defines an inner helix diameter that issubstantially constant across the length of the helical member.
 4. Thesystem of claim 2, wherein the elongate needle member comprises a firsthelical member that defines an inner helix diameter that varies acrossthe length of the helical member.
 5. The system of claim 3, wherein theinner helix diameter is between about 5 mm and about 60 mm.
 6. Thesystem of claim 5, wherein the inner helix diameter is between about 10mm and about 20 mm.
 7. The system of claim 2, wherein the elongateneedle member comprises a first helical member that is comprised of anelongate member formed into the helical shape, the elongate memberhaving an outer diameter.
 8. The system of claim 7, wherein the elongatemember has a cross sectional shape selected from the group consistingof: a circular cross section, an elliptical cross section, a squarecross section, and a rectangular cross section.
 9. The system of claim7, wherein the outer diameter is between about 0.5 mm and about 3 mm.10. The system of claim 7, wherein the helical shape comprises a numberof helical turns advanceable into tissue relative to the insertionmember that is between about 1 and about
 3. 11. The system of claim 3,wherein the helical shape has a substantially constant helix pitch alongthe length of the helical shape.
 12. The system of claim 3, wherein thehelical shape has a substantially variable helix pitch along the lengthof the helical shape.
 13. The system of claim 4, wherein the helicalshape has a substantially constant helix pitch along the length of thehelical shape.
 14. The system of claim 4, wherein the helical shape hasa substantially variable helix pitch along the length of the helicalshape.
 15. The system of claim 11, wherein the helix pitch is betweenabout 5 mm and about 20 mm.
 16. The system of claim 15, wherein thehelix pitch is between about 7 mm and about 13 mm.
 17. The system ofclaim 1, wherein a distal end of the first helical member comprises asharpened tip configured to easily dive into and cross portions of thetissue structure.
 18. The system of claim 7, wherein the elongate membercomprises a solid cross-sectional construct.
 19. The system of claim 7,wherein the elongate member comprises a tubular construct having aninner diameter and as well as the outer diameter.
 20. The system ofclaim 18, wherein the elongate member comprises a material selected fromthe group consisting of: stainless steel, nitinol alloy, titanium,cobalt chrome, and polymer composite.
 21. The system of claim 19,wherein the elongate member comprises a material selected from the groupconsisting of: stainless steel, nitinol alloy, titanium, cobalt chrome,and polymer composite.
 22. The system of claim 1, wherein the insertionmember comprises a substantially rigid construct.
 23. The system ofclaim 1, wherein the insertion member comprises a flexible construct.24. The system of claim 1, wherein the distally protruding shape featureis configured to concentrate interfacial stresses upon the tissuestructure such that the portions of the tissue structure adjacent thedistal tip of the elongate needle member become locally strained aboutthe distally protruding shape feature as the distally protruding shapefeature is advanced into contact with the adjacent tissue structureportions; and wherein the contact between the adjacent tissue structureportions and the distally protruding shape feature locally increases theavailable angle of penetration defined between the needle and a surfaceof the adjacent tissue structure portions.
 25. The system of claim 24,wherein at least one surface of the distally protruding shape featurecomprises a surface configuration selected from the group consisting of:a portion of a spherical surface, a linear ramp surface, an arcuate rampsurface, a multi-stepped ramp surface, and a single-stepped rampsurface.
 26. The system of claim 25, wherein the surface configurationis helically wrapped about a longitudinal axis of the helical member.27. The system of claim 24, wherein at least one surface of the distallyprotruding shape feature comprises a substantially perpendicular leadingsurface.
 28. The system of claim 24, wherein the distally protrudingshape feature has a cross sectional profile comprising a cross sectionalshape selected from the list consisting of: a rectangle, a square, ahalf circle, a triangle, a polygon, a rounded rectangular shape, arounded square shape, and a multi-arcuate shape.
 29. The system of claim1, wherein the distal tip substantially bisects the portion of thedistally protruding shape feature.
 30. The system of claim 1, whereinthe distally protruding shape feature and distal tip of the elongateneedle member are operatively coupled such that the distal tip ismovably coupled adjacent a portion of the distally protruding shapefeature.
 31. The system of claim 25, wherein the distal tip of theelongate needle member is configured to follow a path substantiallyparallel to the surface configuration of the distally protruding shapefeature.
 32. The system of claim 24, wherein the distally protrudingshape feature comprises one or more tissue traction features configuredto prevent relative motion between the distally protruding shape featureand portions of the tissue structure with which it may be directlyinterfaced.
 33. The system of claim 32, wherein at least one of the oneor more tissue traction features comprises a barb.